hdu1078 FatMouse and Cheese —— 记忆化搜索

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1078

代码1：

#include<stdio.h>//hdu 1078 记忆化搜索
#include<string.h>
#define MAX(a,b) (a>b?a:b)

int n,k,dp[105][105],a[105][105];

int dfs(int i,int j)
{
    if(dp[i][j]) return dp[i][j];
    dp[i][j] = a[i][j];

    for(int m = 1;m<=k; m++)
    {
        if( i+m>=1 && i+m<=n && a[i+m][j]>a[i][j] ) dp[i][j] = MAX(dp[i][j],a[i][j]+dfs(i+m,j));
        if( i-m>=1 && i-m<=n && a[i-m][j]>a[i][j] ) dp[i][j] = MAX(dp[i][j],a[i][j]+dfs(i-m,j));
        if( j+m>=1 && j+m<=n && a[i][j+m]>a[i][j] ) dp[i][j] = MAX(dp[i][j],a[i][j]+dfs(i,j+m));
        if( j-m>=1 && j-m<=n && a[i][j-m]>a[i][j] ) dp[i][j] = MAX(dp[i][j],a[i][j]+dfs(i,j-m));
    }
    return dp[i][j];
}

int main()
{
    while(scanf("%d %d",&n,&k) && (n!=-1 || k!=-1))
    {
        for(int i = 1; i<=n; i++)
        for(int j = 1; j<=n; j++)
            scanf("%d",&a[i][j]);
        memset(dp,0,sizeof(dp));
        printf("%d
",dfs(1,1));
    }
    return 0;
}

代码2：

#include<stdio.h>//hdu 1078 记忆化搜索
#include<string.h>
#define MAX(a,b) (a>b?a:b)

int n,k,dp[105][105],a[105][105],d[4][2] = {1,0,-1,0,0,1,0,-1};

int dfs(int i,int j)
{
    if(dp[i][j]) return dp[i][j];
    dp[i][j] = a[i][j];

    for(int t = 1; t<=k; t++)
    for(int m = 0; m<4; m++)
    {
        int x = i+d[m][0]*t, y = j+d[m][1]*t;
        if(x>=1 && x<=n && y>=1 && y<=n && a[x][y]>a[i][j])
            dp[i][j] = MAX(dp[i][j], a[i][j]+dfs(x,y));
    }
    return dp[i][j];
}

int main()
{
    while(scanf("%d %d",&n,&k) && (n!=-1 || k!=-1))
    {
        for(int i = 1; i<=n; i++)
        for(int j = 1; j<=n; j++)
            scanf("%d",&a[i][j]);
        memset(dp,0,sizeof(dp));
        printf("%d
",dfs(1,1));
    }
    return 0;
}