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;}