zoukankan      html  css  js  c++  java
  • UVA 10285 Longest Run on a Snowboard(记忆化搜索)

    Problem C

    Longest Run on a Snowboard

    Input: standard input

    Output: standard output

    Time Limit: 5 seconds

    Memory Limit: 32 MB

    Michael likes snowboarding. That's not very surprising, since snowboarding is really great. The bad thing is that in order to gain speed, the area must slide downwards. Another disadvantage is that when you've reached the bottom of the hill you have to walk up again or wait for the ski-lift.

    Michael would like to know how long the longest run in an area is. That area is given by a grid of numbers, defining the heights at those points. Look at this example:

     1  2  3  4 5
    16 17 18 19 6
    15 24 25 20 7
    14 23 22 21 8
    13 12 11 10 9

    One can slide down from one point to a connected other one if and only if the height decreases. One point is connected to another if it's at left, at right, above or below it. In the sample map, a possible slide would be 24-17-16-1 (start at 24, end at 1). Of course if you would go25-24-23-...-3-2-1, it would be a much longer run. In fact, it's the longest possible.

    Input

    The first line contains the number of test cases N. Each test case starts with a line containing the name (it's a single string), the number of rows R and the number of columns C. After that follow R lines with C numbers each, defining the heights. R and C won't be bigger than100N not bigger than 15 and the heights are always in the range from 0 to 100.

    For each test case, print a line containing the name of the area, a colon, a space and the length of the longest run one can slide down in that area.

    Sample Input
    2
    Feldberg 10 5
    56 14 51 58 88
    26 94 24 39 41
    24 16 8 51 51
    76 72 77 43 10
    38 50 59 84 81
    5 23 37 71 77
    96 10 93 53 82
    94 15 96 69 9
    74 0 62 38 96
    37 54 55 82 38
    Spiral 5 5
    1 2 3 4 5
    16 17 18 19 6
    15 24 25 20 7
    14 23 22 21 8
    13 12 11 10 9

    Sample Output

    Feldberg: 7
    Spiral: 25

    题意:给定一些高度的坡,能从高的滑倒低的,并且只能往四周滑,问最多能滑几个坡。

    思路:记忆化搜索,搜索过程记录下每个坡能滑的最大次数。

    代码:

    #include <stdio.h>
    #include <string.h>
    
    const int d[4][2] = {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
    int t, n, m, map[105][105], vis[105][105], x, y, ans;
    char name[105];
    
    void dfs(int x, int y, int num) {
        for (int i = 0; i < 4; i ++) {
    	int xx = x + d[i][0], yy = y + d[i][1];
    	if (map[xx][yy] < map[x][y] && xx >= 0 && xx < n && yy >= 0 && yy < m && num + 1 > vis[xx][yy]) {
    	    vis[xx][yy] = num + 1;
    	    if (ans < vis[xx][yy])
    		ans = num + 1;
    	    dfs(xx, yy, num + 1);    
    	} 
        }
    } 
    int main() {
        scanf("%d%*c", &t);
        while (t --) {
    	ans = 0;
    	memset(map, 0, sizeof(map));
    	memset(vis, 0, sizeof(vis));
    	scanf("%s%d%d", name, &n, &m);
    	for (int i = 0; i < n; i ++)
    	    for (int j = 0; j < m; j ++)
    		scanf("%d", &map[i][j]);
    	for (int i = 0; i < n; i ++)
    	    for (int j = 0; j < m; j ++) {
    		if (vis[i][j] <= 1) {
    		    vis[i][j] = 1;
    		    dfs(i, j, 1);
    		}
    	    }
    	printf("%s: %d
    ", name, ans);
        }
        return 0;
    }





  • 相关阅读:
    LCD时序中设计到的VSPW/VBPD/VFPD/HSPW/HBPD/HFPD总结【转】
    【读书笔记::深入理解linux内核】内存寻址【转】
    解决阿里云无法正常使用samba的问题【转】
    谈谈Linux内核驱动的coding style【转】
    linux下使用indent整理代码(代码格式化)【转】
    gcc编译选项【转】
    DirectFB简介以及移植[一]【转】
    Android Framebuffer介绍及使用【转】
    Windows Live Writer离线博客工具使用教程(适用于博客园、CSDN、51CTO等等博客)【转】
    jenkins 入门教程(上)【转】
  • 原文地址:https://www.cnblogs.com/keanuyaoo/p/3281465.html
Copyright © 2011-2022 走看看