#include<iostream>
#include<string>
#include<map>
#include<vector>
#include<algorithm>
#include<queue>
#include<set>
#include<stack>
using namespace std;


int main() {

    int num;
    cin >> num;
    int arr[100001];
    for (int i = 0; i < num; i++) {
        cin 
 
>> arr[i];
    }
    
    sort(arr, arr + num);
    reverse(arr, arr + num);


    int matrix[100][100];
    fill(matrix[0], matrix[0]+10000, 0);
    int m = sqrt(num);
    int n;
    for (m; num%m != 0; m--) {
    }

    n = num / m;
    int a, b,i;
    i = a = b = 0;
    int index = 1;
    while (i < num) {
        
 
while (b < m && index == 1 && matrix[a][b]==0) {
            
            matrix[a][b] = arr[i];
            b++;
            i++;
            if (b == m || matrix[a][b] != 0) {
                index = 2;
                a++;
                b--;
                
            }
        }
        
        
 
while (a < n && index == 2 && matrix[a][b] == 0) {
            
            matrix[a][b] = arr[i];
            a++;
            i++;
            if (a==n || matrix[a][b] != 0) {
                index = 3;
                b--;
                a--;
            }
        }
        
        while (b>=0 && index == 3 && matrix[a][b] == 0) {
            
            matrix[a][b] = arr[i];
            b--;
            i++;
            if (b==-1|| matrix[a][b] != 0) {
                index = 4;
                
                a--;
                b++;
            }
        }

        while (a >= 0 && index == 4 && matrix[a][b] == 0) {

            matrix[a][b] = arr[i];
            a--;
            i++;
            if (a == -1 || matrix[a][b] != 0) {
                index = 1;
                b++;
                a++;
                
            }
        }
        
    }


    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            if (j != m - 1) {
                cout << matrix[i][j]<<‘ ‘;
            }

            else {
                cout << matrix[i][j];
            }
            
        }
        cout << endl;
    }


    system("pause");
    
}

填矩陣。。。還是挺簡單的，就是上在邊界的情況處理要小心一點，經常搞錯，要往後退一位，再向新的方向進一位才能到正確的位置。。。

PAT 1105