Pat 1065 a+b and C (64bit) (20 points) (16 points)

because A、B Of ⼤⼩ by [-2^63, 2^63],⽤long long Storage A and B Value , And the value they add sum：
If A > 0, B < 0 perhaps A < 0, B > 0,sum It is impossible to overflow
If A > 0, B > 0,sum It might spill over ,sum The scope should be (0, 2^64 – 2], The result of overflow should be [-2^63, -2]
It's a negative number , therefore sum < 0 It means overflow
If A < 0, B < 0,sum It might spill over , Empathy ,sum The result of overflow is ⼤ On 0 Of , therefore sum > 0 It means that it overflows

#include <iostream>
using namespace std;

int main() {
    
    int n;
    cin>>n;
    for(int i=0;i<n;i++){
    
        long long a,b,c;
        cin>>a>>b>>c;
        long long sum=a+b;
        if(a>0&&b>0&&sum<0){
    
            printf("Case #%d: true\n", i + 1);
        } else if(a < 0 && b < 0 && sum >= 0){
    
            printf("Case #%d: false\n", i + 1);
        } else if(sum > c) {
    
            printf("Case #%d: true\n", i + 1);
        } else {
    
            printf("Case #%d: false\n", i + 1);
        }
    }
    return 0;
}