PAT(甲级)1065 A+B and C (64bit) （20 分)

Given three integers A, B and C in [−2​63​​,2​63​​], you are supposed to tell whether A+B>C.

Input Specification:

The first line of the input gives the positive number of test cases, T (≤10). Then T test cases follow, each consists of a single line containing three integers A, B and C, separated by single spaces.

Output Specification:

For each test case, output in one line Case #X: true if A+B>C, or Case #X: false otherwise, where X is the case number (starting from 1).

Sample Input:

3
1 2 3
2 3 4
9223372036854775807 -9223372036854775808 0

Sample Output:

Case #1: false
Case #2: true
Case #3: false

简析：主要是利用溢出来判断就可以了。问题不大

#include<iostream>
using namespace std;
int main()
{
    int n;
    cin >> n;
    int cnt = 1;
    while(n--)
    {
        long long a, b, c;
        cin>>a>>b>>c;
        long long res = a + b;
        bool flag;
        if(a>0&&b>0&&res<0)
            flag = true;
        else if(a<0 && b<0 && res >= 0)
            flag = false;
        else if(res > c)
            flag = true;
        else
            flag = false;
        if(flag == true)
             printf("Case #%d: true\n", cnt++);
        else
             printf("Case #%d: false\n", cnt++);
    }
    return 0;
}