uva 825 Walking on the Safe Side（动态规划：记忆化搜索）

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#define MAXN 1010
using namespace std;

char str[MAXN];
int a[MAXN][MAXN], dp[MAXN][MAXN];

int dfs(int i, int j) {
if(dp[i][j] > 0)
return dp[i][j];
if(i<1 || j<1)
return 0;
int ans = 0;
if(a[i-1][j] == 0)
ans += dfs(i-1, j);
if(a[i][j-1] == 0)
ans += dfs(i, j-1);
return dp[i][j] = ans;
}

int main(void) {
char ch;
int T, x, tmp, m, n;
scanf("%d", &T);
while(T--) {
getchar();
scanf("%d%d", &m, &n);
getchar();
memset(a, 0, sizeof(a));
for(int i=1; i<=m; ++i) {
scanf("%d", &x);
gets(str);
int len = strlen(str);
int cnt = 0;
for(int j=0; j<=len; ++j) {
if(str[j]-'0'>=0 && str[j]-'0'<=9)
cnt = cnt*10+str[j]-'0';
else {
a[x][cnt] = 1;
cnt = 0;
}
}
}
memset(dp, 0, sizeof(dp));
dp[1][1] = 1;
printf("%d\n", dfs(m, n));
if(T) puts("");
}
return 0;
}