URAL 1221 Malevich Strikes Back! (暴力枚举)

#include <stdio.h>#define MAX_SIZE 101#define FABS(x) ( (x) > 0 ? (x) : -(x) )int paper[MAX_SIZE][MAX_SIZE];int isFigure(int half, int centralRow, int centralColumn){int row, column, bound;for (row = centralRow - half; row <= centralRow + half; row++){//边界先减后增的变换用到了绝对值bound = centralColumn - half +  FABS(row - centralRow);for (column = centralColumn - half; column < bound; column++)if (paper[row][column] == 0)return 0;bound = centralColumn + half -  FABS(row - centralRow);for (column < centralColumn - half +  FABS(row - centralRow); column <= bound; column++)if (paper[row][column] == 1)return 0;for (column = centralColumn + half; column > bound; column--)if (paper[row][column] == 0)return 0;}return 1;}int main(){freopen("input.txt", "r", stdin);int paperSize;while (scanf("%d", &paperSize) != EOF && paperSize != 0){int row, column;for (row = 1; row <= paperSize; row++)for (column = 1; column <= paperSize; column++)scanf("%d", &paper[row][column]);//枚举figure的size和中心位置，枚举的思想是多么的重要啊int found = 0;int figureSize, half, bound, centralRow, centralColumn;for (figureSize = paperSize & 1 ? paperSize : paperSize - 1; figureSize >= 3; figureSize -= 2){half = figureSize >> 1;bound = paperSize - half;for (centralRow = half; centralRow <= bound; centralRow++)for (centralColumn = half; centralColumn <= bound; centralColumn++)if (isFigure(half, centralRow, centralColumn)){found = 1;goto isFound;}}isFound:if (found)printf("%d\n", figureSize);elseprintf("No solution\n");}return 0;}