杨辉三角

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main() {
    int **a;

    int n = 10;
    a = (int **)malloc(sizeof(int *) * n);
    memset(a, 0, sizeof(int *)*n);
    for (int i=0; i<n; ++i) {
        a[i] = (int *)malloc(sizeof(int) * n);
        memset(a[i], 0, sizeof(int) * n);
    }

    // 杨辉三角 计算方式必须保证数字集和已经初始化为0
    for (int i=0; i<n; ++i) {
        for (int j=i; j>0; --j) {
            a[i][j] = a[i-1][j-1] + a[i-1][j];
        }
        a[i][0] = 1;
    }

    int u=4;
    for (int i=0; i<n; ++i) {
        printf("%*s", (n-i-1) * u, " ");
        for (int j=0; j<=i; ++j) {
            printf("%-*d%*s", u, a[i][j], u, " ");
        }
        putchar('\n');
    }

    return 0;
}