hdoj 5630 Rikka with Chess【思维】

Rikka with Chess

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others)

Total Submission(s): 503 Accepted Submission(s): 420

Problem Description

Yuta gives Rikka a chess board of size n×m.

As we all know, on a chess board, every cell is either black or white and every two cells that share a side have different colors.

Rikka can choose any rectangle formed by board squares and perform an inversion, every white cell becomes black, and vice versa.

Rikka wants to turn all cells into the same color, please tell Rikka the minimal number of inversions she need to achieve her goal.

Input

The first line contains a number T(T≤10) ——The
number of the testcases.

Each testcase contains two numbers n,m(n≤109,m≤109).

Output

For each testcase, print a single number which represents the answer.

Sample Input

3
1 2
2 2
3 3

Sample Output

1
2
2

Source

BestCoder Round #73 (div.2)

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
int main()
{
int t;
scanf("%d", &t);
while(t--)
{
int n, m;
scanf("%d%d", &n,&m);
printf("%d\n", n/2+m/2);
}
return 0;
}