UVa OJ 10035 Primary Arithmetic

UVa OJ 10035 

Problem B: Primary Arithmetic

Children are taught to add multi-digit numbers from right-to-left one digit at a time. Many find the "carry" operation - in which a 1 is carried from one digit position to be added to the next - to be a significant challenge. Your job is to count the number of carry operations for each of a set of addition problems so that educators may assess their difficulty.

Input

Each line of input contains two unsigned integers less than 10 digits. The last line of input contains 0 0.

Output

For each line of input except the last you should compute and print the number of carry operations that would result from adding the two numbers, in the format shown below.

Sample Input

123 456
555 555
123 594
0 0

Sample Output

No carry operation.
3 carry operations.
1 carry operation.

计算两个十进制整数在相加时需要多少次进位。每个输入的整数不超过9个数字。

注意int的上限是2147483647，因此可以用整数来保存输入，每次把a和b分别模10就能获取它们的个位数。

#include <cstdio>
#include <cstdlib>
#include <cstring> 

using namespace std;

int main(int argc, char *argv[])
{
    int a, b;
    while (scanf("%d%d", &a, &b) == 2)
    {
        if (!a && !b)
            break;
        int c = 0, ans = 0;
        for (int i = 9; i >= 0; --i)
        {
            c = (a%10 + b%10 + c) > 9 ? 1 : 0;    // c是进位
            ans += c;
            a /= 10;
            b /= 10; 
        }
        if (ans == 0)
            printf("No carry operation.\n");
        else if (ans == 1)
            printf("%d carry operation.\n", ans);
        else
            printf("%d carry operations.\n", ans);
    } 
    //system("pause");
    return 0;
}