提交记录 #101

#include<stdio.h>
void return_matrix(int a[][30], int n) {
    int top = 0, bottom, left = 0, right,//矩形大小
        L = 0, r, t, b;//四个赋值用的变量
    int count = 1;//用于从1开始赋值
    bottom = n - 1; right = n - 1;
    if(n==2){
        a[0][0]=1;
        a[0][1]=2;
        a[1][0]=4;
        a[1][1]=3;
    }
    else if(n==1) a[0][0]=1;
    else {
        while (!(top == bottom && left == right)) {//回型赋值
        while (L <= right) {
            a[top][L] = count;
            count++;
            L++;
        }
        if (count <= n * n) { top++; t = top; }
        while (t <= bottom) {
            a[t][right] = count;
            count++;
            t++;
        }
        if (count <= n * n) { right--; r = right; }
        while (r >= left) {
            a[bottom][r] = count;
            count++;
            r--;
        }
        if (count <= n * n) { bottom--; b = bottom; }
        while (b >= top) {
            a[b][left] = count;
            count++;
            b--;
        }
        if (count <= n * n) { left++; L = left; }
    }
    if (n % 2 != 0) { a[top][left] = count; }
    }//对n为单数的情况进行最后一项的赋值
}
int main() {
    int a[30][30];//暂定为一个小型矩阵，所以二维数组小一点
    int n = 0;//用户输入矩阵边长
    scanf("%d", &n);
    return_matrix(a, n);
    for (int i = 0; i < n; i++) {//遍历输出
        int j;
        printf(" "); 
        for (j = 0; j < n-1; j++) {
            printf("%3d ", a[i][j]);
        }
        printf("%3d\n", a[i][j]);
    }
    return 0;
}