【2月12日PAT刷题笔记】——1065 A+B and C (64bit) (20分) 正负溢出的问题

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

小知识点：

long long的最大值：9223372036854775807（-2^63-1）
long long的最小值：-9223372036854775808 ( 2^63-1)

int 的最大值 2147483647( 2^31-1)

int 的最大值-2147483648 (-2^32-1)

当两个正数之和变成了负数，证明发生了负向溢出，这时一定大于第三个数

当两个负数之和变成了正数，证明发生了正向溢出，这时一定小于第三个数