11538 Chess QueenYou probably know how the game of chess is played and how chess queen operates. Two chess queensare in attacking position when they are on same row, column or diagonal of a chess board. Supposetwo such chess queens (one black and the other white) are placed on (2 × 2) chess board. They can bein attacking positions in 12 ways, these are shown in the picture below:Figure: in a (2 × 2) chessboard 2 queens can be in attacking position in 12 waysGiven an (N × M) board you will have to decide in how many ways 2 queens can be in attackingposition in that.InputInput le can contain up to 5000 lines of inputs. Each line contains two non-negative integers whichdenote the value of M and N (0 < M, N ≤ 106) respectively.Input is terminated by a line containing two zeroes. These two zeroes need not be processed.OutputFor each line of input produce one line of output. This line contains an integer which denotes in howmany ways two queens can be in attacking position in an (M × N) board, where the values of M andN came from the input. All output values will t in 64-bit signed integer.Sample Input2 2100 2232300 10000 0Sample Output121090710011514134000
关于公式大白书上有推导过程。。详见大白书
AC代码：
#include <cstdio>#include <cstring>#include <iostream>//用于cin/cout，，因为这样可以与平台无关的读写64bit整数，更为方便 #include <algorithm>//为了使用swap #define ULL unsigned long long //最大可以保存到2的64次方减1，如果是long long则是到2的63次方减1 using namespace std; int main(){ULL n, m;while(cin >> n >> m){if(!n && !m) break;if(n > m) swap(n, m);//避免分情况讨论 cout << n * m * (m + n – 2) + 2 * n * (n-1) *(3 * m – n – 1) / 3 << endl;}return 0;}
你让我尝到了每时每刻想你的疼苦，
