C/C++对一个整数求出每一位的数值

 Write a program that reads an integer with 3 digits and adds all the digits in the integer.For example,if an integer is 932,the sum of all its digits is 9+3+2=14.

 An integer x.(100<=x<=999)

 The sum of all x's digits

 Use the % operator(求余) to extract digits, and use the / operator(取整除法) to remove the extracted digit. For instance,932 % 10 = 2 and 932 / 10 = 93.

代码：

#include <iostream> 
using namespace std;


int main()
{
	int a,b,c,d;
	cin>>a;
	b = a % 10; 
	//cout<<b<<endl;
	int temp1 = a / 10;
	c = temp1 % 10;
	//cout<<c<<endl;
	int temp2 = temp1 / 10;
	d = temp2 % 10;
	//cout<<d<<endl;
	cout<<b+c+d<<endl;
	return 0;
}

解题关键是“%” 和 “/”两个操作，利用“/”可以将一个百位数逐一去掉最后的一位，然后再用“%”操作算出最后一位的数值。