题目
Given three integers A, B and C in [-263, 263], 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
须要考A+B虑溢出的问题。可能是上界。也可能是下界。
能够考虑string模拟大数的方法,代码用了一种适用于两个元素的投机方法。
代码:
#include <iostream> using namespace std; int main() { int n; cin>>n; long long a,b,c; int i,j; for(i=0;i<n;i++) //一种投机取巧的办法。仅适用于两个元素 { cin>>a>>b>>c; cout<<"Case #"<<i+1<<": "; if(a>0&&b>0&&a+b<a&&a+b<b) //上越界,必定大于c cout<<"true\n"; else if(a<0&&b<0&&a+b>a&&a+b>b) //下越界,必定小于c cout<<"false\n"; else if(a+b>c) //常规比較 cout<<"true\n"; else cout<<"false\n"; } return 0; }