uva 825 - Walking on the Safe Side(dp)

时间:2023-05-29 23:19:20

题目链接:825 - Walking on the Safe Side

题目大意:给出n,m,现在给出n行数据, 每行有k(k为不定值)个数字, 第一个数字代表行数, 后面k - 1个数代表当前行的这个位置不可走, 问有多少路径可以从(1,1)到(n,m),只能向下或向右。

解题思路:dp[i][j] = dip[i - 1][j] + dp[i][j - 1], 很简单的dp问题。

#include <stdio.h>
#include <string.h>
const int N = 1005; int n, m, dp[N][N], g[N][N]; void handle(int k, char str[]) {
int len = strlen(str), num = 0;
for (int i = 0; i <= len; i++) {
if (str[i] >= '0' && str[i] <= '9')
num = num * 10 + str[i] - '0';
else {
g[k][num] = 1;
num = 0;
}
}
} void read() {
int r;
char str[N];
memset(dp, 0, sizeof(dp));
memset(g, 0, sizeof(g));
scanf("%d%d", &n, &m);
for (int i = 0; i < n; i++) {
scanf("%d", &r);
gets(str);
handle(r, str);
}
} int solve () {
dp[0][1] = 1;
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= m; j++) {
if (g[i][j]) continue;
dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
}
}
return dp[n][m];
} int main() {
int cas;
scanf("%d", &cas);
while (cas--) {
read();
printf("%d\n", solve());
if (cas) printf("\n");
}
return 0;
}