******************************************************************************
* 简单题（包括枚举，二分查找，（复杂）模拟，基础数据结构（栈、队列），杂题等 * ******************************************************************************
1001 A+B
1002 A+B+C
1009 Fat Cat
1010 The Angle
1011 Unix ls
1012 Decoding Task
1019 Grandpa's Other Estate
1034 Simple Arithmetics
1036 Complete the sequence!
1043 Maya Calendar
1054 Game Prediction
1057 Mileage Bank
1067 Rails
1078 u Calculate e
1080 Digital Roots
1084 Booklet Printing
1085 Finding Rectangles
1094 Packets
1095 Crosswords
1100 Simply Syntax
1101 TEX Quotes
1104 Expanding Fractions
1105 Egyptian Multiplication
1107 Prime Cuts
1109 Uniform Generator
1112 Centipede Collisions
1117 Octal Fractions
1128 Perfect Cubes
1131 Basically Speaking
1135 Data Bugs
1138 LC-Display
1142 S-Trees
1148 Gridland
1152 The Blocks Problem
1153 Ecological Bin Packing
1154 The Skyline Problem
1159 Tree Summing
1160 Power of Cryptography
1161 Simulation Wizardry
1162 Climbing Trees
1165 Mutant Flatworld Explorers
1166 Greedy Gift Givers
1167 Pipe Fitters
1168 Trees on the level
1172 The Errant Physicist
1173 ``Accordian'' Patience
1174 Software CRC
1176 Roman Roulette
1179 The Dole Queue
1187 Mouse Clicks
1189 Student Grants
1190 Gondwanaland Telecom
1199 Recycling
1206 Traffic Lights
1209 Cola
1214 Fibonacci Coding
1216 Where's the Marble
1219 A Flea on a Chessboard
1221 Perfect Pth Powers
1224 Crazy Tea Party
1238 Border
1241 Factorial Frequencies
1243 Extrapolation Using a Difference Table
1246 Inventory Maintenance
1247 Perfection
1250 Hi-Q
1251 Polynomial Showdown
1254 Mapmaker
1257 Board Silly
1259 Equation Elation
1260 18-Wheeler Caravans (aka Semigroups) （数据与题目描述有差异，暂时不要做了，否则会 PE 至死...）
1261 Transferable Voting
1263 Crypto Columns
1268 Pushing Boxes
1271 Biker's Trip Odometer
1272 Candy Sharing Game
1280 Unreliable Message
1284 Molecular Formula
1291 Who's the Boss?
1302 Sum of Factorials
1305 A Contesting Decision
1309 Helping Florida
1312 Reserve Roman Notation
1318 Moving Tables
1321 Parencodings
1331 Deck
1334 Ratio
1338 Trees Made to Order
1357 Calling Extraterrestrial Intelligence Again
1365 Digital Product
1370 Candy
1374 Rain
1375 K-In-A-Row
1384 Palindrome Number
1386 Gossipers
1392 Easy Task
1401 Gigantic Sums
1403 Palindromes
1404 M*A*S*H
1408 Pi
1409 Up and Down Sequences
1410 Machined Surfaces
1413 Word Index
1415 Does This Make Me Look Fat?
1423 The Hardest Problem Ever
1425 Polar Explorer
1430 World's Worst Bus Schedule
1435 Integer Inquiry
1442 Lotto
1443 Matrix Chain Multiplication
1449 Equation Solver
1452 Tree Recovery
1453 Artificial Intelligence?
1456 Team Queue
1457 Error Correction
1458 France '98
1459 Goldbach's Conjecture
1462 Bee Maja
1471 Simple Computers
1474 How Many Fibs?
1477 All in All
1480 Diplomatic License
1481 Polygon Programming with Ease
1486 The Longest SubSequence
1489 ATDS （数据很弱，模拟即可过。但正确的做法是凸包 + 旋转卡壳）
1491 Good Approximation Problem
1492 Power Cable Problem
1504 Family Tree
1511 Average is not Fast Enough!
1512 Bound Found
1513 Code the Tree
1514 Decode the Tree
1518 Hard to Believe, but True!
1522 Edge
1526 Drink, on Ice
1527 Bean Counting
1528 Factoring Large Numbers
1529 Maze Traversal
1536 Substitution Cypher
1540 AutoFish
1545 Contest Scoreboard
1550 Pousse
1554 Request for Proposal
1555 Australian Voting
1557 The Trip （卡精度，输入上须做特殊处理）
1584 Hanoi Tower Troubles Again! （可以推出公式，但正确的做法是二分图最小路径覆盖）
1595 There's Treasure Everywhere!
1596 Video Surveillance
1599 Box of Bricks
1604 Cable Master
1612 The Tree Movers
1623 Blowing Fuses
1626 Programmer, Rank Thyself
1628 Magnificent Meatballs
1629 Safecracker
1631 Tanning Salon
1637 HangOver
1648 Booklets
1655 Yeehaa!
1657 Formula Racing
1674 Ball Toss
1685 Flow Layout
1688 Speed Limit
1696 No Brainer
1702 Team Rankings
1703 To and Fro
1716 Ride to School
1722 The Peanuts
1725 Argus
1730 The Separator in Grid
1732 Orders
1741 Magic Trick
1744 Grandpa is Famous
1746 Filling Out the Team
1757 Y2K Accounting Bug （貌似是 DP，但是工大数据较弱，模拟可以混过去）
1764 Soundex
1766 Dog & Gopher
1768 Mine Sweeper
1776 Steps
1788 Death to Binary?
1793 Inglish-Number Translator
1794 Japan Plotter Driver
1796 Hanafuda Shuffle
1802 The Balance （有数学解法）
1804 Leaky Cryptography
1813 Primary Arithmetic
1830 Bridge Hands
1832 Building a New Depot
1840 Kaleidoscope
1848 Jolly Jumpers
1850 Interpreter
1853 WERTYU
1863 整数的排序
1864 Fibonacci
1870 Race （可用 STL next_permutation 算法水过去，不过貌似有数学解法）
1871 整数的表示
1881 Ones
1882 All Integer Average
1888 The Counting Problem
1896 Average Speed
1905 Stack 'em Up
1930 Forests
1933 Election
1934 Nash Equilibrium
1937 Repeatless Numbers
1939 任务的分配
1944 方程题！！
1951 Beavergnaw
1955 Tic Tac Toe
1958 Faucet Flow
1959 Equations
1962 Above Average
1963 Time Zones
1967 Basic
1968 Rock, Scissors, Paper
1970 Persistent Numbers
1973 Guessing Game
1976 Calendar
1981 Inversion
1985 Super Calculator
1988 Drawing Rectangles
1997 Multiplying Matrices
1999 Data Manager
2009 Deduction
2011 Simple Problem
2012 Sort and Merge
2015 Crossed ladders
2017 Peter's smokes
2020 Chessboard in FEN
2026 Specialized Four-Digit Numbers
2028 Boundaries on 'A New Kind of Science'
2029 Rate of Return
2030 A Card Trick
2035 Center of Symmetry
2036 Polynomial Remains
2039 Grandpa's Rubik Cube
2043 Noise Effect
2045 Ambiguous permutations
2058 Diagonal Primes
2059 Encrypting in a Safe Way
2060 Fibonacci Problem Again
2065 Fibonacci Number
2066 Word Reversal
2069 Jimmy's Riddles
2071 Keep on Truckin'
2072 Blurred Vision
2075 Finding Nemo
2076 Series Determination
2080 Ferry Loading III
2081 Pick-up sticks
2082 Rock-Paper-Scissors Tournament
2088 Delta-wave
2089 4th point
2092 Gopher and hawks
2094 Common permutation
2098 Ultra-QuickSort
2100 Beat the Spread!
2101 Traditional BINGO
2102 Brownie Points I
2105 Bungee Jumping
2107 Crashing Robots
2111 Electrical Outlets
2115 Playground
2117 Long Division
2119 Acrophobic Cows
2121 War on Weather
2125 Prerequisites?
2127 Ball bearings
2129 Sylvester construction
2134 Hardware
2138 Jackpot
2142 Linear world
2151 Scrabble
2154 Dropping tests
2158 Do it!
2161 On Storing Clothes
2163 4 Values whose Sum is 0
2171 Rotate and Cut
2173 Interpreting Control Sequences
2174 Tornado!
2176 Pascal Library
2179 Where Are My Genes
2180 Computer DJ
2183 Extrusion
2191 Consecutive Digits in a Rational Number
2201 Sum of Cubes
2202 Bold ASCII Lines
2212 It's My Derivative
2213 The Game
2215 Dice Stacking
2217 The Happy Worm
2221 Ohgas' Fortune
2223 Numeral System
2232 Queens, Knights and Pawns
2251 Not Only Shops I
2260 GongZhu
2264 Standing
2266 Scientific counting method
2267 Alice and Bob
2277 Another Apples
2283 Emag eht htiw Em Pleh
2286 Help Me with the Game
2290 Laserbox
2293 Reduced ID Numbers
2296 Up the Stairs
2300 Dihedral groups
2302 Flavius Josephus Reloaded
2303 Wine trading in Gergovia
2304 Homogeneous squares
2309 Knights of the Round Table
2312 Gaus in Elementary School
2313 Kick-Tipp
2314 Stamps
2323 01000001
2324 The Bank of Kalii
2326 Kindergarten Graduation （直接构造）
2327 brainf*ck
2331 Sequence Sum Possibilities
2332 Ancient Keyboard
2333 Best SMS to Type
2334 Changing Phone Numbers
2335 Dramatic Multiplications
2343 Book Replacement
2352 Ferry Loading IV
2353 Card Hands （标准做法好像是 Trie 树）
2356 How many 0's?
2363 House Numbers
2364 Rotten Ropes
2368 A DP Problem
2371 9-18
2386 The Cow Lineup
2391 Aggressive cows
2395 WFF 'N PROOF
2398 Rectilinear polygon
2410 Make it Manhattan
2411 Quick Change
2412 Triangular Sums
2413 Shuffle'm Up
2422 Mahershalalhashbaz, Nebuchadnezzar, and Billy Bob Benjamin Go to the Regionals
2424 Plaque Pack
2428 An Introduction
2433 Full of Energy
2435 Helping the fish
2437 Quicksum
2438 Linear Pachinko
2439 Surprising Strings
2443 Root of the Problem
2450 Kickdown
2453 Nasty Hacks
2455 Card Trick （本人的做法比较 WS，笔算结果后直接打表 -_-b ）
2462 Easier Done Than Said?
2463 Colorville
2475 Simple Calendar
2476 Hurdles Race
2485 Myacm Triangles
2487 Loansome Car Buyer
2489 Robot Motion
2491 Fibonacci
2492 Football
2496 Tic-Tac-Toe
2497 Team Arrangement
2498 Barbara Bennett's Wild Numbers
2502 Chessboard Dance
2505 Kadj Squares
2516 Citystar
2519 Fake coin
2520 Little bailey I
2521 Little bailey II
2527 A simple problem
2528 1 2 and 3
2529 How Many Ways （需要了解计算机内二进制数的表示法）
2531 Accident I
2537 Kart
2540 Only One Boat （直接构造）
2541 Merry Christmas
2545 Just for Checksum
2546 The right time
2556 X-unappeared
2557 inflate
2562 Thanks giving Day
2564 Regional Ranklist
2567 Pell
2568 LFSR
2569 Next Number
2573 Life Game
2575 Divide
2578 Super_Stack
2579 Earn more!
2580 Divisibility
2585 Jogger
2588 Mispelling
2589 Conversions
2590 Encoding
2591 Decoding
2592 Flipping Burned Pancakes
2597 Savings Account
2598 Elementary Additions
2600 Coin Toss
2601 GPA
2602 Tree Grafting
2603 Look and Say
2607 Wavelet Compression
2616 Tower Parking
2619 Smeech
2623 An easy problem
2633 Puzzle I
2636 Puzzle II
2640 Have a Good Time
2641 Hidden Markov Model
2651 Pie
2654 Printer Queue
2659 My Favourite Code
2660 WORD
2661 Two Sides
2674 Ranking
2680 Cartesian Sum
2684 Cache
2689 Nail I
2691 Nail III （用 multiset 代替平衡树）
2694 Antimonotonicitye
2695 Humidex
2696 Tour de France
2699 Conformity
2709 Rectangular Polygons
2728 Antiarithmetic?
2729 One is an Interesting Number
2730 Verdis Quo
2734 Rout 66
2737 The Final Countdown
************
* 贪心算法 *
************
1003 Mixing Milk
1052 Radar Installation
1062 数列极差问题
1065 Entropy
1096 Intervals
1225 Supermarket
1314 Wooden Sticks
1349 Gone Fishing
1913 Intervals
1941 超市收银问题
2051 Expedition
2143 Songs
2160 Bin Packing
2164 Keep the Customer Satisfied
2244 Get the Colors
2359 Yogurt factory
2490 Saruman's Army
2587 Change
2620 The Dragon of Loowater
2625 P=DP
2675 Stock
2677 Instruction Set
***************************************************************
* 动态规划（包括线性 DP，环状 DP，树状 DP 以及状态压缩 DP 等）*
***************************************************************
1005 Fast Food
1031 Piggy-Bank
1042 I-KeyBoard
1058 Number Triangles
1061 Fat Cat's cousin II
1090 The Staircases
1141 Dividing up
1158 History Grading
1163 Unidirectional TSP
1181 Ugly Numbers
1192 Dollars
1215 Health Power
1227 Common Subsequence
1249 Optimal Array Multiplication Sequence
1264 Decorations
1277 Rhyme Schemes
1288 Bridging Signals
1297 Special Experiment
1316 Human Gene Functions
1400 Minimizing Maximizer （正确的做法是点树 + DP，但 HOJ 数据有误，DP 过不了，只能贪心）
1402 整数划分问题
1438 The Tower of Babylon
1444 Humble Numbers
1447 Compromise
1485 A Good Helper
1496 World Cup Noise
1525 Largest Rectangle in a Histogram
1537 Is Bigger Smarter?
1562 Tiling Up Blocks
1579 Chopsticks
1585 Euro Efficiency
1590 Pearls
1593 Triangles
1598 Always On the Run
1603 Brackets Sequence
1644 City Game
1680 One Person 'The Price is Right'
1697 Alphacode
1711 Investment
1733 Phone numbers
1738 Land Division Tax
1754 To Europe! To Europe!
1755 Test the Rods
1760 The jackpot
1780 Decoding Morse Sequences
1795 Ferry Loading
1839 Jack
1852 Tight Words
1893 Tian Ji -- The Horse Racing
1894 Islands and Bridges
1911 Polygon
1912 Density map
1936 Brackets
1942 OS进程调度
1965 Ferry Loading II
1977 Recaman's Sequence
1978 Terrible Sets
1987 Recursive Function
1990 Kids Grouping
1993 lykoo
2000 Maximum Submatrix
2014 Tiling
2023 Zipper
2024 Lenny's Lucky Lotto Lists
2044 Supermarket
2048 Decorate the wall
2056 Bookshelf
2067 Adding 1s, 2s, and 3s
2074 Exact Change Only
2085 Wavio Sequence
2091 Chess
2124 Tri Tiling
2139 Spiderman's workout （搜索也可以过，但要有好的剪枝）
2145 Tour
2148 Computer Transformation
2188 WordStack
2195 Pascal's Travels
2196 Job Scheduling by Open Bidding
2219 Mini Locomotive
2226 Cleaning Robot
2257 Sorting
2262 Spanning trees in a fan
2317 Pimp My Ride
2372 Recoup Traveling Expenses
2376 Chinese Word Segmentation
2406 The Bavarian Beer Party
2419 Margaritas on the River Walk
2421 Hie with the Pie
2473 Fish Can Fly
2481 Travel
2494 Spam
2500 Party at Hali-Bula （此题有多种解法）
2503 Bribing FIPA
2506 Print Words in Lines
2514 Perfect Service
2544 Leave an Increasing Sequence
2547 New Term （此题较综合，除状态压缩 DP 外还包含 Dijkstra 以及拓扑排序等算法，是道不错的题）
2555 Eating Watermelon
2558 maxsum
2559 prefix
2560 stamps
2566 Farmer
2572 Naive Robot
2574 Sales Promotion
2582 Game Dice
2583 Baking Cakes
2595 Tiling a Grid With Dominoes
2615 Obfuscation
2630 Training of Lord Fish's Fan I
2637 Calculate Similarity
2646 Isolated Word Recognition
2662 Pieces Assignment
2664 Taking Exercise
2665 Factory of XiaoE
2669 Dice Password Security
2698 Exchange Rates
*****************************************************************
* 搜索（包括简单递归，BFS，DFS 以及回溯 + 剪枝，迭代加深搜索等）*
*****************************************************************
1018 Multiple
1022 Spacecraft Malfunction
1025 Skew Binary
1028 Secret Code
1030 Labyrinth
1044 Transportation
1049 Sticks
1053 Holedox Moving
1075 The Castle
1083 N-Credible Mazes
1097 Robot
1103 Cat and Mouse
1116 Alien Security
1121 Erdos Numbers
1134 Maze
1140 The Game
1149 T9
1175 Krypton Factor
1183 Street Numbers
1185 Bandwidth
1200 All Squares
1232 Jugs
1256 Run, Run, Runaround Numbers
1289 Vase Collection
1354 Forgetful
1361 Map of Ninja House
1412 LED Test
1422 Asteroids!
1440 Knight Moves
1448 Dungeon Master
1455 The Settlers of Catan
1465 Euro Cup 2000
1472 Mondriaan's Dream
1476 Hike on a Graph
1487 Fleet Commander
1488 TMD
1500 Strange Towers of Hanoi
1505 Push!!
1524 Genetic Code
1538 File Fragmentation
1547 FatMouse and Cheese
1574 Gift?!
1597 Pushing Boxes
1619 The Die Is Cast
1620 It's not a Bug, It's a Feature!
1639 Image Perimeters
1678 Knockout Tournament
1690 Relative Relatives
1692 Choose Your Own Adventure
1720 Pollution
1723 Finding Nemo
1736 A Game on the Chessboard
1797 Red and Black
1835 Paper Cutting
1892 The Rotation Game
1908 Party Lamps
1931 A Star not a Tree?
1949 Hay Points
1950 Jogging Trails
1956 Square
1957 Blocks
1974 Matrix
2004 Words Group
2013 Turn Over Turn Over
2022 Mersenne Composite Numbers
2027 Jill's Tour Paths
2040 This Sentence is False
2042 I hate SPAM, but some people love it
2049 Any fool can do it
2064 Journey to Tibet
2073 The Door/Key Problem
2087 Cube in Labyrinth
2095 Security Panel
2096 Roads in the North （求树的直径）
2120 Is It A Tree?
2123 Walk Through the Forest
2144 Sudoku
2157 RSI
2159 The mysterious X network
2166 Black Box
2172 Consecutive Ones
2177 ICPC Strikes Again
2190 Connect
2199 Sudoku
2205 Plinko （DP 也可做）
2208 Pegs
2230 Countdown
2238 Go
2240 Flipping colors
2254 Win or Lose
2256 The Game
2263 Sudoku
2298 Basic wall maze
2306 Tudoku （硬搞貌似也能过）
2308 Mine Map
2310 Honeymoon Hike
2315 A Knight's Journey
2325 The Cubic End
2336 Entertainment
2377 Triumvirate Canyon Interlocution
2400 Tautology
2414 Push Button Lock
2426 Snakes on a Plane
2434 Going to know him
2442 Go Go Gorelians
2459 Honeycomb Walk
2461 The Triangle Game
2464 Falling Leaves
2495 Sudoku
2504 Treasure of the Chimp Island
2510 Route Planning
2518 Holiday Gifts
2524 bailey's trouble II
2552 Filling Numbers
2581 Go
2604 Server Relocation
2612 Escape from Enemy Territory
2631 Training of Lord Fish's Fan II （此题有 DP 做法，具体方法请咨询 wywcgs 教主）
2643 Bi-image
2655 Prime Path
2658 Military Buildings
2666 Average Distance
2667 Bus Pass
2672 Pachinko
2703 Strange Billboard
2706 Key Task
2732 Another Brick in the Wall （此题还有其他做法）
2733 The Sidewinder Sleeps Tonite
*************************************************
* 数学（包括数论，组合数学，离散数学，博弈论等）*
*************************************************
1004 Prime Palindromes
1006 Weird Clock
1008 How Many N
1013 Just The Facts
1014 Niven Numbers
1015 Nearly prime numbers
1016 Joseph's problem I
1017 Joseph's problem II
1039 Factorial
1069 Prime Land
1076 Ordered Fractions
1087 Self Numbers
1126 Smith Numbers
1155 国家利益
1156 The Cat in the Hat
1196 Power Crisis
1198 Permalex
1205 Factors and Factorials
1262 百万雄师过大江
1296 Big Number
1317 Flip and Shift
1348 Biorhythms
1356 Prime Judge
1367 A Stone Game
1391 Boastin' Red Socks
1441 Eeny Meeny Moo
1446 Binomial Showdown
1470 Let it Bead
1483 Paths on a Grid
1519 Assistance Required
1533 Fibonacci Numbers
1543 Dick and Jane
1552 Prime Distance
1560 Factovisors
1610 Twenty Questions
1649 Count on Canton
1669 In Danger
1761 Number Sequence
1769 Choose and Divide
1787 C Looooops
1827 The Clocks
1842 Raising Modulo Numbers
1866 猩猩点灯
1900 A Multiplication Game
1945 孔明棋
1953 Relatives
1960 Euclid's Game
1980 Game of Connections
1991 Happy 2005
1994 Monochromatic Triangles
1995 Venn Diagram
2010 GCD & LCM Inverse
2110 The Embarrassed Cryptographer
2116 Countable Numbers
2122 Factstone Benchmark
2153 Nim
2167 Ignore the Garbage
2204 Fibonacci Numbers
2253 Choices
2261 Coin changing
2276 Count prime
2282 Divisors
2305 Diophantus of Alexandria
2322 Incomplete chess boards
2342 Sum of Consecutive Prime Numbers
2373 Thieves Co. Ltd
2397 Semi-prime H-numbers
2416 Visible Lattice Points
2436 I love you
2467 Z-curve
2477 String's Puzzle
2515 Number tricks
2561 MaoLaoDa Number
2576 Simple Computing
2577 Simple Computing II
2593 Monkey Vines
2624 Triplets
2628 Fibonacci Convolution
2635 Weights
2647 Megaminx
2657 Leonardo's Notebook
2668 Cutting Banknotes
2700 Pseudoprime numbers
2708 Weird Numbers
2718 Smart Ray
2719 Tickets
************
* 计算几何 *
************
1027 Equipment Box
1032 Lifting the Stone
1099 Lining Up
1143 Area
1188 Orchard Trees
1248 Intersecting Lines
1310 Three Sides Make a Triangle
1387 Billiard
1439 The Circumference of the Circle
1451 Globetrotter
1503 Lost in Space
1517 Global Roaming
1544 Leaps Tall Buildings
1587 Hansel and Grethel
1633 Transmitters
1707 Watchdog
1750 Line of Sight
1773 Airline Hub
1935 Triangle
2016 Conic Distance
2054 Stacking Cylinders
2155 Box walking
2203 Cover the Square
2258 Rotating
2328 Stacking Cylinders
2571 Triangle
2627 SVM
2639 Billiards
2721 Roll-A-Big-Ball
******************************************************************************
* 字符串处理（包括最小表示法，中、后缀表达式转换、Trie 树或 STL map 的运用等 *
******************************************************************************
1081 Scramble Sort
1088 Do the Untwist
1089 Word Amalgamation
1110 Excuses, Excuses!
1132 Letter Sequence Analysis
1133 Mark-up
1191 ID Codes
1201 Ananagrams
1204 Word Crosses
1213 Path
1223 Hidden Password
1244 Evaluating Simple C Expressions
1307 Choose Your Words Carefully
1337 Web Navigation
1347 487-3279
1389 Election
1466 Friends
1468 HTML
1469 Anagram Groups
1515 Etaoin Shrdlu
1530 Compound Words
1548 Crypt Kicker II
1634 W's Cipher
1656 Magic Trick
1670 Run Length Encoding
1684 Symmetric Order
1880 Zipf's Law
1898 Babelfish
1929 Hardwood Species
1952 Power Strings
1989 The Most Frequent Word
2046 Bullshit Bingo
2057 Complicated Translation
2114 Necklace Decomposition
2149 Anagrammatic Distance
2181 Take Your Vitamins
2184 Pasting Strings
2189 Single Digit Adder
2206 Defining Moment
2241 Crabbles
2297 Automatic Correction of Misspellings
2318 Scavenger Hunt
2320 Rdeaalbe
2405 Digital Friends
2408 Decompression
2441 Frugal Search
2449 Java vs C++
2465 Instruens Fabulam
2488 Automatic Editing
2511 Shift Cipher
2525 bailey's trouble III
2551 Zoogle
2570 Inverted Files
2693 Open Source
2710 Reaus! Sham! Beaux!
2725 Help!
********* 图论 *********
无向图的割点、桥：
1007 SPF
1098 NetWork
1789 Electricity
2360 Redundant Paths
二分图匹配：
1021 Housing Complexes
1056 Machine Schedule
1086 Don't Get Rooked
（暴搜也可以过）
1624 Sorting Slides
1708 Taxi Cab Scheme
1710 Card Game Cheater
1851 Gopher II
1859 Knights
2025 Going Home
2077 T-Shirt Gumbo
2295 Guardian of Decency
2349 Muddy Fields
2407 Evacuation
2472 IR-Lab2501 Against Mammoths
2542 Allocate Dormitories
欧拉（回）路：
1033 Play on Words
1045 John's trip
1426 Door Man
1903 Snow Clearing
1966 Catenyms
2021 Colored Sticks
拓扑排序：
1114 Frame Stacking
1170 Following Orders
1336 Sorting It All Out
1352 Mystery
1943
平面上的点
1992 Dependency Problems
2078 Window Pains
最小生成树（Prim, Kruskal）：
//1614 Communication Planning for Phobos
1632 Jungle Roads
1658 Picnic Planning
（度限制最小生成树，Prim + 贪心）
1751 Tangled in Cables
1811 Freckles
1833 Truck History
1961 Arctic Network
2162 Buy or Build
2507 The Bug Sensor Problem （POJ 加强了此题的数据，必须用 O(nlogn) 的 ”Voronoi
图求平面最小生成树“算法才可过）
最短路径（Bellman-Ford, Dijkstra, Floyd）：
1068 King （差分约束系统）
//1113 Stockbroker Grapevine
1125 Railroad
1130 Galactic Import
1164 The Postal Worker Rings Once
1202 Route Finding
1211 HIT's Powerstation
1236 Domino Effect
1252 The Doors
1436 MPI Maelstrom
1437 Arbitrage
1450 Frogger
1460 Heavy Cargo
1464 From Dusk Till Dawn
1494 Hinge Node Problem
1516 Fiber Network
1565 The Geodetic Set Problem
1566 Cave Raider
1653 Heavy Transportation
1735 Sightseeing trip
1763 Fire Station
1948 回家
2041 Will Indiana Jones Get There?
2047 106 miles to Chicago
2062 Help the Hurricane Victims
（求第二短路）
2218 Median Weight Bead
2486 Exchange Rates
2493 Robot
2534 Stone III
2727 Test
网络流：
1228 Power Network
1294 Sightseeing Tour
1345 A Plug for UNIX
2543 Stone IV
2609 March of the Penguins
2634 How to earn more
2713 Matrix1
2716 xiaoE's Sweet Game
2717 Take Bus to The Nest
染色问题：
1115 Channel Allocation
1266 Phone Home
2055 Astonishing Movie Plan
邻接阵的幂的意义及运用：
1171 Numbering Paths
1617 Acceptable Strings
树的同构判定：
1292 Subway Tree Systems
2-SAT:
1917 Peaceful Commission
2632 Blanks in a Table
比赛图：
1303 Task Sequences
顶点的度的灵活运用：
2420 Caterpillar
求生成树的个数：
2535 Spanning Tree I
2536 Spanning Tree II