思维题 Gym 100553A Alter Board

题目传送门

 /*

     题意：一个n×m的矩形，相邻的颜色不同，黑或白。问最少的翻转次数，每次翻转可指定任意一个子矩形

     思维题：最少要把偶数行和列翻转，也就是n/2+m/2次

 */

 #include <cstdio>

 using namespace std;

 int main(void)        //Gym 100553A Alter Board

 {

 //    freopen ("A.in", "r", stdin);

     freopen ("alter.in", "r", stdin);

     freopen ("alter.out", "w", stdout);

     int n, m;

     while (scanf ("%d%d", &n, &m) == )

     {

         printf ("%d\n", n /  + m / );

         for (int i=; i<=n; i+=)

         {

             printf ("%d %d %d %d\n", i, , i, m);

         }

         for (int i=; i<=m; i+=)

         {

             printf ("%d %d %d %d\n", , i, n, i);

         }

     }

     return ;

 }