UVa 465 Overflow (比较大小难道不应该用double吗)

465 - Overflow

Time limit: 3.000 seconds

http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=97&page=show_problem&problem=406

Write a program that reads an expression consisting of two non-negative integer and an operator. Determine if either integer or the result of the expression is too large to be represented as a ``normal'' signed integer (type integer if you are working Pascal, type int if you are working in C).

Input

An unspecified number of lines. Each line will contain an integer, one of the two operators + or *, and another integer.

Output

For each line of input, print the input followed by 0-3 lines containing as many of these three messages as are appropriate: ``first number too big'', ``second number too big'', ``result too big''.

Sample Input

300 + 3
9999999999999999999999 + 11

Sample Output

300 + 3
9999999999999999999999 + 11
first number too big
result too big

如标题所述。

完整代码：

/*0.019s*/

#include<cstdio>
const double maxint = -1u >> 1;

char str[600];

int main()
{
	double a, b;
	char op;
	while (gets(str))
	{
		puts(str);
		sscanf(str, "%lf %c %lf", &a, &op, &b);
		if (a > maxint) puts("first number too big");
		if (b > maxint) puts("second number too big");
		if (op == '+' && a + b > maxint || op == '*' && a * b > maxint) puts("result too big");
	}
	return 0;
}