UVA 10401 Injured Queen Problem

UVA_10401

    这个题目本身并不难，但是如果用gets读的话要注意输入里面有空行。

#include<stdio.h>
#include<string.h>
#include<ctype.h>
#define MAXD 20
char b[MAXD];
int N;
long long int f[MAXD][MAXD];
void solve()
{
    int i, j, k, r;
    long long int res;
    N = strlen(b);
    memset(f, 0, sizeof(f));
    if(b[0] == '?')
    {
        for(i = 0; i < N; i ++)
            f[0][i] = 1;
    }
    else
    {
        if(isdigit(b[0]))
            j = b[0] - '1';
        else
            j = b[0] - 'F' + 14;
        f[0][j] = 1;
    }
    for(i = 1; i < N; i ++)
    {
        if(b[i] == '?')
        {
            for(j = 0; j < N; j ++)
            {
                for(k = 0; k < j - 1; k ++)
                    f[i][j] += f[i - 1][k];
                for(k = j + 2; k < N; k ++)
                    f[i][j] += f[i - 1][k];
            }
        }
        else
        {
            if(isdigit(b[i]))
                j = b[i] - '1';
            else
                j = b[i] - 'F' + 14;
            for(k = 0; k < j - 1; k ++)
                f[i][j] += f[i - 1][k];
            for(k = j + 2; k < N; k ++)
                f[i][j] += f[i - 1][k];
        }
    }
    res = 0;
    for(i = 0; i < N; i ++)
        res += f[N - 1][i];
    printf("%lld\n", res);
}
int main()
{
    while(scanf("%s", b) == 1)
    {
        solve();
    }
    return 0;
}