[Explanations] - AcWing - 753. square matrix I

753. square matrix I

Title Description

Enter an integer N, back to shape the output of a two-dimensional array of order N.

1 is in the outermost array, the outer layer is two times, and so on.

Input Format

Comprising multiple input lines, each comprising an integer N.

When the input behavior of N = 0, it indicates the end of input, and the line without any treatment.

Output Format

For each input integer N, the output of a two-dimensional array to meet the requirements of the N-th order.

Each array occupy N rows, each row containing N integers separated by spaces.

After each array output is completed, it outputs a blank line.

data range

0 ≤ N ≤ 100

Sample input:

1
2
3
4
5
0

Sample output:

1

1 1
1 1

1 1 1
1 2 1
1 1 1

1 1 1 1
1 2 2 1
1 2 2 1
1 1 1 1

1 1 1 1 1
1 2 2 2 1
1 2 3 2 1
1 2 2 2 1
1 1 1 1 1

Difficulty: hard
Time / space restrictions: 1s / 64MB
By the total number: 79
The total number of attempts: 170
Source: grammar questions
Algorithms Tags: Array

AC Code

#include <iostream>
#include <cstdio>
using namespace std;
int main(void)
{
    int n, arr[105][105] = {0}, i, j;
    while(scanf("%d",&n) != EOF){
        if(n == 0){
            break;
        }
        for(i = 1; i <= n; i ++){
            for(j = i; j <= n - i + 1; j ++){
                arr[j][i] = i;
                arr[i][j] = i;
                arr[j][n - i + 1] = i;
                arr[n - i + 1][j] = i;
                //二重循环内的内容是为了遍历到外围的内容
                //i是输出的内容变量第一层外围都是1.第二层外围都是2，以此类推。
            }
        }
        for(i = 1; i <= n; i ++){
            for(j = 1; j <= n; j ++){
                cout<<arr[i][j]<<" ";
            }
            cout<<endl;
        }
        cout<<endl;
    }
    return 0;
}

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