Va 11538 chess Queen

Put two attacking queens on the n × m board and ask how many methods are there

This question focuses not on programming, but on the derivation of mathematical formulas. The formula of Σ (I2) is also used. It seems that I didn't learn mathematics in high school.

As for the derivation process, read the White Paper. By the way, there seems to be a small error in the book, but it does not affect the result.

1 // # define local 2 # include <iostream> 3 # include <algorithm> 4 using namespace STD; 5 6 int main (void) 7 {8 # ifdef local 9 freopen ("11538in.txt", "r", stdin); 10 # endif11 12 unsigned long n, m; 13 while (CIN> N> m) 14 {15 if (n + M = 0) break; 16 if (n> m) Swap (n, m ); 17 cout <m * n * (m + N-2) + 2 * n * (n-1) * (3 * m-n-1)/3 <Endl; 18} 19 Return 0; 20}

Code Jun

 

Va 11538 chess Queen