PAT-A1065题解

-简单模拟

PAT-A1065. A+B and C (64bit) (20)
【时间限制】
100 ms
【内存限制】
65536 kB
【代码长度限制】
16000 B
【题目描述
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

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题目解析：这题和乙级其中的一题类似，区别在于这道题给定的范围过大。相加可能会导致溢出。因此需要在题意的基础上加上对于数据溢出的考量

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AC代码：

		long long a,b,c;
		scanf("%lld%lld%lld",&a,&b,&c);
		long res=a+b;
		bool flag;
		if(a>0&&b>0&&res<0)			//正溢出 
			flag=true;
		else if(a<0&&b<0&&res>=0)	//负溢出 
			flag=false;
		else if(res>c)				//无溢出 
			flag=true;
		else 
			flag=false;
		if(flag==true){
			printf("Case #%d: true\n",tcase++);
		}
		else{
			printf("Case #%d: false\n",tcase++);
		}
	}
	return 0;
}