下面这段程序为什么会运行出错？

Question

如题
题目是要输出一个螺旋形的矩阵
比如输入4， 输出就是
1 2 3 4
12 13 14 5
11 16 15 6
10 9 8 7

include

#include
using namespace std;
int main()
{
int **a, n, i, j, k = 1;

cin >> n;
if(n > 120) cin >> n;
a = new int *[n];
for (i = 0; i < n; ++i) a[i] = new int [n];

for(i = 0; i < n; ++i) for(j = 0; j < n; ++j) a[i][j] = 0;

i = j = 0;

while(k <= n * n){
    while(i < n && j >= 0) {
        if(a[j][i] != 0) break;
        a[j][i] = k;
        ++i;
        ++k;
    }
    i -= 1; j += 1;

    while(j < n && j >= 0){
        if(a[j][i] != 0) break;
        a[j][i] = k;
        ++j;
        ++k;
    }
    j -= 1; i -= 1;

    while(i < n && i >= 0){
        if(a[j][i] != 0) break;
        a[j][i] = k;
        --i;
        ++k;
    }
    i += 1; j -= 1;

    while(i < n && i >= 0){
        if(a[j][i] != 0) break;
        a[j][i] = k;
        --j;
        ++k;
    }
    j += 1; i += 1;
}
cout << endl;

for(i = 0; i < n; ++i) {
    for(j = 0; j < n; ++j) cout << setw(6) << a[i][j];
    cout << endl;
}


for(i = 0; i < n; ++i) delete [] a[i];
delete [] a;

return 0;

}

Answer 1

你这没有出错，是不是你的头文件没导入
#include
#include "iostream"
最开始加上这两行