10783 - Odd Sum
Time limit: 3.000 seconds
Given a range [a, b], you are to find the summation of all the odd integers in this range. For example, the summation of all the odd integers in the range [3, 9] is 3 + 5 + 7 + 9 = 24.
Input
There can be at multiple test cases. The first line of input gives you the number of test cases,
T
( 1T100
). Then T test cases follow. Each test case consists of 2 integers
a
and
b
( 0ab100
) in two separate lines.
Output
For each test case you are to print one line of output - the serial number of the test case followed by the summation of the odd integers in the range [a, b]
.
Sample Input
2
1
5
3
5
Sample Output
Case 1: 9
Case 2: 8
完整代码：
/*0.006s*/
#include <cstdio>
int main(void)
{
int t, a, b;
scanf("%d", &t);
for (int i = 1; i <= t; ++i)
{
scanf("%d%d", &a, &b);
a >>= 1, b = (b + 1) >> 1;
printf("Case %d: %d\n", i, b * b - a * a);
}
return 0;
}