99乘法

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int sum = 0;
            int sum2 = 0;
            int[] arr1 = new int[10];
            int[,] arr2 = new int[10,10];
            for (int i = 1; i <= 9; i++)
            {
                sum = sum + i;
                for (int j = 1; j <= 9; j++)
                {
                    sum2 = sum2 + j;
                    arr2[i, j] = i * j;
                    Console.WriteLine(+i+"*"+j+"="+arr2[i,j]);
                   
                }
            }
        }
    }
}

1~100總和

#include<stdio.h>
#include<conio.h>
int main()
{
    int i;
    int sum=0;
    for( i=1; i<=100; i++)
    {
    sum=sum+i;
    }
    printf("%d\n",sum);
    getch();   
    return 0;  
}