squarefk模拟赛

sequence

　 　 没有压位的高精度居然Ａ了，数据很善良嘛。标准解法是多次随机一个大素数取模来避免高精度。

var t,i:longint;
const f:array[1..1000] of integer
=(2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,101,103,107,109,113,127,131,137,
139,149,151,157,163,167,173,179,181,191,193,197,199,211,223,227,229,233,239,241,251,257,263,269,271,277,
281,283,293,307,311,313,317,331,337,347,349,353,359,367,373,379,383,389,397,401,409,419,421,431,433,439,
443,449,457,461,463,467,479,487,491,499,503,509,521,523,541,547,557,563,569,571,577,587,593,599,601,607,
613,617,619,631,641,643,647,653,659,661,673,677,683,691,701,709,719,727,733,739,743,751,757,761,769,773,
787,797,809,811,821,823,827,829,839,853,857,859,863,877,881,883,887,907,911,919,929,937,941,947,953,967,
971,977,983,991,997,1009,1013,1019,1021,1031,1033,1039,1049,1051,1061,1063,1069,1087,1091,1093,1097,1103,
1109,1117,1123,1129,1151,1153,1163,1171,1181,1187,1193,1201,1213,1217,1223,1229,1231,1237,1249,1259,1277,
1279,1283,1289,1291,1297,1301,1303,1307,1319,1321,1327,1361,1367,1373,1381,1399,1409,1423,1427,1429,1433,
1439,1447,1451,1453,1459,1471,1481,1483,1487,1489,1493,1499,1511,1523,1531,1543,1549,1553,1559,1567,1571,
1579,1583,1597,1601,1607,1609,1613,1619,1621,1627,1637,1657,1663,1667,1669,1693,1697,1699,1709,1721,1723,
1733,1741,1747,1753,1759,1777,1783,1787,1789,1801,1811,1823,1831,1847,1861,1867,1871,1873,1877,1879,1889,
1901,1907,1913,1931,1933,1949,1951,1973,1979,1987,1993,1997,1999,2003,2011,2017,2027,2029,2039,2053,2063,
2069,2081,2083,2087,2089,2099,2111,2113,2129,2131,2137,2141,2143,2153,2161,2179,2203,2207,2213,2221,2237,
2239,2243,2251,2267,2269,2273,2281,2287,2293,2297,2309,2311,2333,2339,2341,2347,2351,2357,2371,2377,2381,
2383,2389,2393,2399,2411,2417,2423,2437,2441,2447,2459,2467,2473,2477,2503,2521,2531,2539,2543,2549,2551,
2557,2579,2591,2593,2609,2617,2621,2633,2647,2657,2659,2663,2671,2677,2683,2687,2689,2693,2699,2707,2711,
2713,2719,2729,2731,2741,2749,2753,2767,2777,2789,2791,2797,2801,2803,2819,2833,2837,2843,2851,2857,2861,
2879,2887,2897,2903,2909,2917,2927,2939,2953,2957,2963,2969,2971,2999,3001,3011,3019,3023,3037,3041,3049,
3061,3067,3079,3083,3089,3109,3119,3121,3137,3163,3167,3169,3181,3187,3191,3203,3209,3217,3221,3229,3251,
3253,3257,3259,3271,3299,3301,3307,3313,3319,3323,3329,3331,3343,3347,3359,3361,3371,3373,3389,3391,3407,
3413,3433,3449,3457,3461,3463,3467,3469,3491,3499,3511,3517,3527,3529,3533,3539,3541,3547,3557,3559,3571,
3581,3583,3593,3607,3613,3617,3623,3631,3637,3643,3659,3671,3673,3677,3691,3697,3701,3709,3719,3727,3733,
3739,3761,3767,3769,3779,3793,3797,3803,3821,3823,3833,3847,3851,3853,3863,3877,3881,3889,3907,3911,3917,
3919,3923,3929,3931,3943,3947,3967,3989,4001,4003,4007,4013,4019,4021,4027,4049,4051,4057,4073,4079,4091,
4093,4099,4111,4127,4129,4133,4139,4153,4157,4159,4177,4201,4211,4217,4219,4229,4231,4241,4243,4253,4259,
4261,4271,4273,4283,4289,4297,4327,4337,4339,4349,4357,4363,4373,4391,4397,4409,4421,4423,4441,4447,4451,
4457,4463,4481,4483,4493,4507,4513,4517,4519,4523,4547,4549,4561,4567,4583,4591,4597,4603,4621,4637,4639,
4643,4649,4651,4657,4663,4673,4679,4691,4703,4721,4723,4729,4733,4751,4759,4783,4787,4789,4793,4799,4801,
4813,4817,4831,4861,4871,4877,4889,4903,4909,4919,4931,4933,4937,4943,4951,4957,4967,4969,4973,4987,4993,
4999,5003,5009,5011,5021,5023,5039,5051,5059,5077,5081,5087,5099,5101,5107,5113,5119,5147,5153,5167,5171,
5179,5189,5197,5209,5227,5231,5233,5237,5261,5273,5279,5281,5297,5303,5309,5323,5333,5347,5351,5381,5387,
5393,5399,5407,5413,5417,5419,5431,5437,5441,5443,5449,5471,5477,5479,5483,5501,5503,5507,5519,5521,5527,
5531,5557,5563,5569,5573,5581,5591,5623,5639,5641,5647,5651,5653,5657,5659,5669,5683,5689,5693,5701,5711,
5717,5737,5741,5743,5749,5779,5783,5791,5801,5807,5813,5821,5827,5839,5843,5849,5851,5857,5861,5867,5869,
5879,5881,5897,5903,5923,5927,5939,5953,5981,5987,6007,6011,6029,6037,6043,6047,6053,6067,6073,6079,6089,
6091,6101,6113,6121,6131,6133,6143,6151,6163,6173,6197,6199,6203,6211,6217,6221,6229,6247,6257,6263,6269,
6271,6277,6287,6299,6301,6311,6317,6323,6329,6337,6343,6353,6359,6361,6367,6373,6379,6389,6397,6421,6427,
6449,6451,6469,6473,6481,6491,6521,6529,6547,6551,6553,6563,6569,6571,6577,6581,6599,6607,6619,6637,6653,
6659,6661,6673,6679,6689,6691,6701,6703,6709,6719,6733,6737,6761,6763,6779,6781,6791,6793,6803,6823,6827,
6829,6833,6841,6857,6863,6869,6871,6883,6899,6907,6911,6917,6947,6949,6959,6961,6967,6971,6977,6983,6991,
6997,7001,7013,7019,7027,7039,7043,7057,7069,7079,7103,7109,7121,7127,7129,7151,7159,7177,7187,7193,7207,
7211,7213,7219,7229,7237,7243,7247,7253,7283,7297,7307,7309,7321,7331,7333,7349,7351,7369,7393,7411,7417,
7433,7451,7457,7459,7477,7481,7487,7489,7499,7507,7517,7523,7529,7537,7541,7547,7549,7559,7561,7573,7577,
7583,7589,7591,7603,7607,7621,7639,7643,7649,7669,7673,7681,7687,7691,7699,7703,7717,7723,7727,7741,7753,
7757,7759,7789,7793,7817,7823,7829,7841,7853,7867,7873,7877,7879,7883,7901,7907,7919);
type num=array[0..4000] of longint;
function  change(s:ansistring):num;
          var a:num;
              len,i:longint;
          begin
          fillchar(a,sizeof(a),0);
          len:=length(s);
          for i:=1 to len do
            a[i]:=ord(s[len-i+1])-ord('0');
          a[0]:=len;
          change:=a;
          end;
function  Plus(a:num;b:longint):num;
          var len,i:longint;
          begin
          len:=a[0];
          for i:=1 to len do
            begin
            inc(a[i],b);
               b:=a[i] div 10;
            a[i]:=a[i] mod 10;
            end;
          while b>0 do
            begin
            inc(len);
            a[len]:=b mod 10;
                 b:=b div 10;
            end;
          a[0]:=len;Plus:=a;
          end;
function  Mul(a:num;b:longint):num;
          var len,x,i:longint;
          begin
          len:=a[0];x:=0;
          for i:=1 to len do
            begin
            a[i]:=a[i]*b+x;
               x:=a[i] div 10;
            a[i]:=a[i] mod 10;
            end;
          while x>0 do
            begin
            inc(len);
            a[len]:=x mod 10;
                 x:=x div 10;
            end;
          a[0]:=len;Mul:=a;
          end;
procedure print(a:num);
          var i:longint;
          begin
          for i:=a[0] downto 1 do
            write(a[i]);
          writeln;
          end;
function  same(a,b:num):boolean;
          var i:longint;
          begin
          if a[0]<>b[0] then exit(false);
          for i:=1 to a[0] do
            if a[i]<>b[i]
              then exit(false);
          same:=true;
          end;
procedure work;
          var n,i,t:longint;
              a,an:num;
              str:ansistring;
              ch:char;
          begin
          read(n,ch);readln(str);
          t:=pos(' ',str);
          a:=change(copy(str,1,t-1));
          an:=change(copy(str,t+1,length(str)-t));
          for i:=1 to n-1 do
            begin
            a:=Mul(Plus(a,f[i]),f[i]);
            if a[0]>an[0]
              then begin
                   writeln('NO');
                   exit;
                   end;
            end;
          if same(a,an)
            then writeln('YES')
            else writeln('NO');
          end;
BEGIN
readln(T);
for i:=1 to T do work;
END.

树链剖分

　 　不得不吐槽题目背景，跟树链剖分完全没有关系。本题正解TreeDP，学到新东西：如果递归爆栈的话，可以拓扑排序后搞。 F[u][0]和F[u][1]分别代表u不向上连边和向上连边时已经搞出来几条链。F[u][0]=min{选两个孩子跟u连边新城一条新的链，其他的不连}，F[u][1]=min{选一个孩子跟u连边把未完成的一条链延长，其他不连}

CONST FileName='tree';
      maxn=100000;
var v,next:array[1..maxn*2] of longint;
    Adjlist,Q:array[1..maxn] of longint;
    F:array[1..maxn,0..1] of longint;
    vis:array[1..maxn] of boolean;
    h,t,n,x,y,tot,i:longint;
procedure build(x,y:longint);
          begin
          inc(tot);v[tot]:=y;
          next[tot]:=Adjlist[x];
          Adjlist[x]:=tot;
          end;
procedure TUOPU;
          var i:longint;
          begin
          h:=0;t:=1;Q[1]:=1;vis[1]:=true;
          while h<t do
            begin
            inc(h);i:=Adjlist[Q[h]];
            while i<>0 do begin
              if not vis[v[i]]
                then begin
                     vis[v[i]]:=true;
                     inc(t);Q[t]:=v[i];
                     end;
              i:=next[i];
              end;
            end;
          end;
procedure DP;
          var sum,temp,cur,i:longint;
              min:array[1..2] of longint;
          begin
          for cur:=t downto 1 do
            begin
            i:=Adjlist[Q[cur]];sum:=0;
            min[1]:=0;min[2]:=0;
            while i<>0 do begin
              inc(sum,f[v[i]][0]);
              temp:=f[v[i]][1]-f[v[i]][0];
              if(temp<min[1])or(min[1]=0)
                then begin
                     min[2]:=min[1];
                     min[1]:=temp;
                     end else
              if(temp<min[2])or(min[2]=0)
                then min[2]:=temp;
              i:=next[i];
              end;
            f[Q[cur]][1]:=sum+min[1];//1代表向上连边
            f[Q[cur]][0]:=sum+min[1]+min[2]+1;
            end;
          end;
BEGIN
readln(n);
for i:=1 to n-1 do
  begin
  readln(x,y);
  build(x,y);
  build(y,x);
  end;
TUOPU;DP;
writeln(f[1][0]);
END.

字串变换

等会写