c语言实现杨辉三角

   int i,j,k;
    //定义一个二维数组
    int a[14][14];
    int n=12;

    //先将两侧的数组置为1
    for (i = 1; i <= n; i++) {
        a[i][1]=a[i][i]=1;
    }

    //中间的数字等于顶上两数之和
    for (j = 3; j <=n; j++) {
        for (k = 2; k<=j-1; k++) {
            a[j][k] = a[j-1][k-1]+a[j-1][k];
        }
    }
    //输出打印
    for (i = 1;  i<=n ; ++i) {
        for ( j = 1; j <= n-i; ++j) {
            printf("   ");
        }
        for ( k = 1; k <=i ; ++k) {
            printf("%6d",a[i][k]);
        }
        printf("\n");
    }