1753 Flip Game

和咱天的HDU 1882 Strange Billboard 差不多

不过这题的数据量要小一些,4*4的规模,用二进制表示完全可以用INT型存

http://acm.pku.edu.cn/JudgeOnline/problem?id=1753

#include <iostream>#include <cstring>using namespace std;char g[4][4];int counter;int temp1,temp2;int start;int find(int x);int d[4] = {0xf000,0x0f00,0x00f0,0x000f};int main(){int i,j,k,m,n,t;while (scanf("%s",g[0])!=EOF){start = 0;//记录开始的状态for (i=0;i<4;i++) //转换前四位15~12{if (g[0][i] == 'b') // 如果是黑色的{start = start | (1<<(15-i));}}k = 11;for (i=1;i<=3;i++) //输入及转换后12位:11~0{scanf("%s",g[i]);}for (i=1;i<=3;i++) //输入及转换后12位:11~0{for (j=0;j<4;j++){if (g[i][j] == 'b') // 如果是黑色的{start = start | (1<<(k));}k--;}}//printf("%d/n",start);//输入及转换完成-----------------------------------int mincount=-1;for (i=0;i<16;i++){//printf("%d/n",counter);//i+((1<<12)-1)if (find(i)) //如果可以达到目标态{if ((counter < mincount) || (mincount == -1)){mincount = counter;}}}if (mincount == -1) //如果一直不可达{//那么printf("Impossible/n");}else{printf("%d/n",mincount);}}return 0;}int find (int x) //参数传第一行的转换方法{int i,j,change1 = 0,change2 = 0,counter1 = 0,counter2 = 0;temp1 = start;temp2 = ~start;for (i=0;i<4;i++) //change each line{if (i == 0) //第一行的转换{change1 = (x<<12);change2 = (x<<12);}else{change1 = temp1&(d[i-1]);//上一行的位情况change2 = temp2&(d[i-1]);temp1 = temp1 & (~d[i-1]);temp2 = temp2 & (~d[i-1]);}//然后开使转化if (i){temp1 ^= change1>>4;temp1 ^= (change1>>(4+1))&d[i];temp1 ^= (change1>>(4-1))&d[i];temp1 ^= (change1>>(4+4))&d[i+1];temp2 ^= change2>>4;temp2 ^= (change2>>(4+1))&d[i];temp2 ^= (change2>>(4-1))&d[i];temp2 ^= (change2>>(4+4))&d[i+1];}else{temp1 ^= change1;temp1 ^= (change1>>1)&d[i];temp1 ^= (change1<<1)&d[i];temp1 ^= (change1>>4)&d[i+1];temp2 ^= change2;temp2 ^= (change2>>1)&d[i];temp2 ^= (change2<<1)&d[i];temp2 ^= (change2>>4)&d[i+1];}//计算counter of changefor (j=0;j<16;j++){if ((change1>>j)&1){counter1++;}if ((change2>>j)&1){counter2++;}}}if (temp1 && temp2 != 0xffff){return 0;}else{if (!(temp1 && temp2 != 0xffff)){counter = counter1<counter2?counter1:counter2;}else if (!temp1){counter = counter1;}elsecounter = counter2;return 1;}}/*test data:wbbwwwbwwbbwwbbbbwwbbbwbbwwbbwwwbbbbbbbbbbbbbbbbwwwwwwwwwwwwwwww*/