XidianOJ 1143 方格填数

--正文

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PS：开始时候，把数组定成了5*5,莫名奇妙的错误，我果然是SB

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm> 
#include <queue>
using namespace std;

int n,k;

int gcd(int a,int b){
    if (a < b) return gcd(b,a);
    if (b == 0) return a;
    else return gcd(b,a % b);
}

bool buhuzhi[10][10];
int arr[10];
int table[10][10] = {0};
bool used[10] = {0};
int total = 0;

bool canPlace(int i,int x,int y){
    if (y == 1){
        if (x == 1){
            return true;
        }
        else {
            if (buhuzhi[table[x-1][y]][i]) return false;
            else return true;
        }
    }
    else {
        if (x == 1){
            if (buhuzhi[table[x][y-1]][i]) return false;
            else return true;
        }
        else {
            if (buhuzhi[table[x][y-1]][i] || buhuzhi[table[x-1][y]][i] )
                return false;
            else 
                return true;
        }
    }
}

void search(int x,int y){
    int i;
    for (i=1;i<=9;i++){
        if (x==1 && y==1){
        //    printf("NOW\n");    
        }
        if (!used[i] && canPlace(i,x,y)){
            used[i] = true;
            if (x == 3){
                if (y == 3){
                    table[x][y] = i;
                    total ++; 
                    used[i] = false;
                    return;
                }
                else {
                    table[x][y] = i;
                    search(1,y+1);
                }
            }
            else {
                table[x][y] = i;
                search(x+1,y);
            }
            used[i] = false;
        }
    }
    return;
}

int main(){
    
    while (scanf("%d %d %d %d %d %d %d %d %d",&arr[1],&arr[2],&arr[3],&arr[4],&arr[5],&arr[6],&arr[7],&
    arr[8],&arr[9]) != EOF) {
        memset(buhuzhi,true,sizeof(buhuzhi));
        memset(table,0,sizeof(table));
        memset(used,false,sizeof(used));
        int i,j;
        for (i=1;i<=9;i++){
            for (j=1;j<=9;j++){
                if (gcd(arr[i],arr[j]) == 1){
                    buhuzhi[i][j] = false;
                    buhuzhi[j][i] = false;
                }
            }
        }
        search(1,1);
        printf("%d\n",total);
        total = 0;
    }
    return 0;
}