Visual Studio Code 出现segmentation fault

Question

这是PTA乙级1019的代码，我在网站上运行时没有问题，但在自己的电脑上的VS Code上运行时就显示segmentation fault，这是为什么
输入示例：6767

#include <stdio.h>
#define MAXSIZE 4

void swap( int * a, int * b);

int main(void){
    int n;
    int max;
    int min;
    int N[MAXSIZE] = {0};

    scanf("%d", &n);
    N[0] = n/1000;  //如何取得各位上的数字
    N[1] = (n/100)%10;
    N[2] = (n/10)%10;
    N[3] = n%10;

    if((N[0]==N[1])&&(N[0]==N[2])&&(N[0]==N[3])){  
        printf("%04d - %04d = 0000",n ,n);
    }

    else{
        do{
            int tag = 0;
            if( tag != 0){
                printf("\n");
            }
            for( int p = MAXSIZE-1; p>=0; p--){  //从小到大排序
                int flag = 0;
                for( int i=0; i<p; i++){
                    if( N[i]>N[i+1]){
                        swap( &N[i], &N[i+1]);
                        flag = 1;
                    }  
                }
                if( flag == 0){
                    break;
                }
            }

            max = N[3]*1000 + N[2]*100 + N[1]*10 + N[0];
            min = N[0]*1000 + N[1]*100 + N[2]*10 + N[3];
            n = max - min;

            N[0] = n/1000;  //如何取得各位上的数字
            N[1] = (n/100)%10;
            N[2] = (n/10)%10;
            N[3] = n%10;
            printf("%04d - %04d = %04d", max, min, n);  
            tag++;
        }while( n != 6174);
    }

    return 0;
}

void swap( int * a, int * b){
    int * t;
    *t = *a;
    *a = *b;
    *b = *t;
}

Answer 1

void swap( int * a, int * b){
    int t;
    t = *a;
    *a = *b;
    *b = t;
}