大佬们，代码运行不了，实在找不到问题在哪了！！

#include<iostream>
using namespace std;
main()
{
    int n,k,i,j;
    int a[101];
    string ans[5];
    scanf("%d",&n);
    for(i=0;i<n;i++) scanf("%d",&a[i]);//数字 

    k=0;
    while(k<n){
        switch(a[k]){
            case 0:ans[0] += "XXX";ans[4] += "XXX";
            ans[1] += "X.X";ans[2] += "X.X";ans[3] += "X.X";break;
            case 1:ans[0] += "..X";ans[4] += "..X";
            ans[1] += "..X";ans[2] += "..X";ans[3] += "..X";break;
            case 2:ans[0] += "XXX";ans[4] += "XXX";
            ans[1] += "..X";ans[2] += "XXX";ans[3] += "X..";break;
            case 3: ans[0] += "XXX";ans[4] += "XXX";
            ans[1] += "..X";ans[2] += "XXX";ans[3] += "..X";break;
            case 4:ans[0] += "X.X";ans[4] += "..X";
            ans[1] += "X.X";ans[2] += "XXX";ans[3] += "..X";break;
            case 5: ans[0] += "XXX";ans[4] += "XXX";
            ans[1] += "X..";ans[2] += "XXX";ans[3] += "..X";break;
            case 6: ans[0] += "XXX";ans[4] += "XXX";
            ans[1] += "X..";ans[2] += "XXX";ans[3] += "X.X";break;
            case 7: ans[0] += "XXX";ans[4] += "..X";
            ans[1] += "..X";ans[2] += "..X";ans[3] += "..X";break;
            case 8:ans[0] += "XXX";ans[4] += "XXX";
            ans[1] += "X.X";ans[2] += "XXX";ans[3] += "X.X";break;
            case 9:ans[0] += "XXX";ans[4] += "XXX";
            ans[1] += "X.X";ans[2] += "XXX";ans[3] += "..X";break;  
        }           

        k++;
    }
    for(i=0;i<n;i++){
        cout<<ans[i];
        printf("\n");
    }
}

/*
字符串数组 
s[] 
*/