回溯____蓝桥 棋盘

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int fenzu[6][6];
int used_fenzu[6][6];//根据分组信息确定第一位;根据字母排列A B C D E F确定第二位;最终依靠本数组实现"组内判重"
int used_row[6][6];//第一位为行数
int used_col[6][6];//第一位为列数
char map[6][6];
int next_row[40];
int next_col[40];
int all = 1;

void print()
{
    int i, j;
    for(i = 0; i < 6; i++){for(j = 0; j < 6; j++){printf("%c",map[i][j]);}printf("\n");}
}

int cango(int r, int c, char ch)
{
    if(used_fenzu[ fenzu[r][c] ][ ch-'A' ] == 1 || used_row[r][ch-'A'] == 1 || used_col[c][ch-'A'] == 1)
        return 0;
    return 1;    
}

void fun(int r, int c, int n)
{
    char ch;
    int i, j;
    
    //printf("r = %d, c = %d, n = %d\n",r,c,n);
    if(n == 36)
    {
        printf("%d\n",all++);
        print();    
        return;
    }

    for(ch = 'A'; ch <= 'F'; ch++)
    {
        if( cango(r, c, ch) )
        {
            map[r][c] = ch;
            used_fenzu[ fenzu[r][c] ][ ch-'A' ] = 1;
            used_row[r][ch-'A'] = 1;
            used_col[c][ch-'A'] = 1;

            fun(next_row[n+1], next_col[n+1], n+1);            

            map[r][c] = 0;
            used_fenzu[ fenzu[r][c] ][ ch-'A' ] = 0;
            used_row[r][ch-'A'] = 0;
            used_col[c][ch-'A'] = 0;
        }
    }

    return;
}

int main()
{
    int N, i, j, temp_N, index;
    freopen("1.txt", "r", stdin);
    memset(map, 0, sizeof(map));

    for(i = 0; i < 6; i++)
    {
        for(j = 0; j < 6; j++)
        {
            scanf("%1d", &fenzu[i][j]);
        }
    }
    scanf("%d", &N);

    temp_N = N;
    while(temp_N--)
    {
        int r, c;
        char ch;

        scanf("%1d%1d%c", &r, &c, &ch);        
        map[r][c] = ch;
        used_fenzu[ fenzu[r][c] ][ ch-'A' ] = 1;
        used_row[r][ch-'A'] = 1;
        used_col[c][ch-'A'] = 1;
    }

    index = N;
    for(i = 0; i < 6; i++)
    {
        for(j = 0; j < 6; j++)
        {
            if( map[i][j]  == 0)
            {
                next_row[index] = i;
                next_col[index] = j;
                index++;
            }
        }
    }    
    fun(next_row[N],next_col[N],N);   
    
    return 0;
}