UVA 825 Walking on the Safe Side

UVA_825

    一个比较容易的计数问题，如果(i,j)这个点可以通过的话f[i][j]=f[i-1][j]+f[i][j-1]，否则f[i][j]=0。

#include<stdio.h>
#include<string.h>
#include<ctype.h>
#define MAXD 1010
char b[10010];
int N, M, G[MAXD][MAXD], f[MAXD][MAXD];
void solve()
{
    int i, j, k;
    gets(b);
    sscanf(b, "%d%d", &N, &M);
    memset(G, 0, sizeof(G));
    for(i = 1; i <= N; i ++)
    {
        gets(b);
        for(j = 0; isdigit(b[j]); j ++);
        while(b[j])
        {
            if(isdigit(b[j]))
            {
                sscanf(b + j, "%d", &k);
                G[i][k] = 1;
                while(isdigit(b[j]))
                    j ++;
            }
            else
                j ++;
        }
    }
    for(i = 0; i <= N; i ++)
        f[i][0] = 0;
    for(i = 0; i <= M; i ++)
        f[0][i] = 0;
    f[1][0] = 1;
    for(i = 1; i <= N; i ++)
        for(j = 1; j <= M; j ++)
        {
            f[i][j] = 0;
            if(!G[i][j])
            {
                f[i][j] += f[i - 1][j];
                f[i][j] += f[i][j - 1];
            }
        }
    printf("%d\n", f[N][M]);
}
int main()
{
    int t;
    gets(b);
    sscanf(b, "%d", &t);
    while(t)
    {
        gets(b);
        solve();
        if(-- t)
            printf("\n");
    }
    return 0;
}