stream usc game

game is carried out in a n*n black-and-white phalanx (as in chess, except that the color is random). You can do two operations on the Matrix at a time: Select any two rows of the matrix, swap the columns of the two lines (that is, the color of the swap grid): Select any column of the matrix, swap the two columns (that is, swap the color of the corresponding lattice) the target of the game, that is, by seve

Title Link: http://acm.hdu.edu.cn/showproblem.php?pid=5294Test Instructions: give you n a tomb, m path, a person in the Tomb of No. 1th (beginning), another person in the tomb of N (end), the beginning of the person only through the shortest path to catch up with the end of the person, and the end of the person can cut off any path. The first question--the end of the person to make the starting point that the person can not catch up the number of paths to be cut, the minimum number of paths to o

;Set the last number to X, operate the T-time, each operation must be a black lattice a white latticeCb*x=sb+tCw*x=sw=tSolution to X= (SB-SW)/(CB=CW)Category discussion:1.CB!=CW get x, Judge the Law (X>=MX) on the line2.CB==CW (this time must be n,m are even), X is not sure(1) SB!=SW no solution(2) SB==SW two x is how much, find the smallest legal xHow to judge an X to be legal:Black-and-white dyeing is a two-part pictures--and X Difference---black lattice--inf--> white lattice--and X difference

Title Link: http://acm.hdu.edu.cn/showproblem.php?pid=5294Test Instructions: give you n a tomb, m path, a person in the Tomb No. 1th (beginning), another person in nTomb (end), the beginning of the person only through the shortest path to catch up with the end of the person, and the end of the person can cut off any path.The first question--the end of the person to make the starting point that the person can not catch up the number of paths to be cut, the minimum number of paths to outputThe sec

Title: Give a chessboard, there are some numbers, each can be adjacent to the two number plus one. The minimum number of questions makes the numbers on the board equal.Idea: The basic idea: the least equal number of two points. The checkerboard black and white staining, each operation will make a sunspot and a white child plus 1, the establishment of a binary map, s to all white dots, all black dots to the t edge, traffic for each point to reach the need for equal number of the size of the deman