2018-09-30 HDOJ 第一天

A+B for Input-Output Practice (I)
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 68537 Accepted Submission(s): 26955

Problem Description
Your task is to Calculate a + b.
Too easy?! Of course! I specially designed the problem for acm beginners.
You must have found that some problems have the same titles with this one, yes, all these problems were designed for the same aim.

Input
The input will consist of a series of pairs of integers a and b, separated by a space, one pair of integers per line.

Output
For each pair of input integers a and b you should output the sum of a and b in one line, and with one line of output for each line in input.

Sample Input
1 5
10 20

Sample Output
6
30

Author
lcy

Recommend
JGShining

#include"stdio.h"

int main()
{
    int a,b;
    while(scanf("%d %d",&a,&b)==2)
    {
        printf("%d\n",a+b);
    }
    return 0;
}

关于scanf：
scanf()函数返回的值为：正确按指定格式输入变量的个数；也即能正确接收到值的变量个数。

while(scanf("%d %d",&a,&b))会导致超时：
当输入为[EOF](通常切的题目有多组数据，会使用[EOF]表示输入结束），这时，没有读取输入，scanf[返回值]是-1，即等价于while(-1)，还会继续循环，所以超时。

不要忘了scanf的时候要加&。