ai2813-画家问题-回溯解法C语言

来源：互联网发布：淘宝的免费开店在哪里编辑：程序博客网时间：2024/06/05 06:43
方法粗陋，时间略长，还望指教。
#include <stdio.h>#include <stdlib.h>int mintimes=225;int nowtimes=0;void collor(int*a){    *a?(*a=0):(*a=1);}void change(int*now,int size){    collor(now);    collor(now+1);    collor(now-1);    collor(now+size+2);    collor(now-size-2);}void searchf(int i,int size,int*wall,int*record)//穷举第一行i~n的所有可能{    void paint(int*wall,int n,int*record);    if(i<=size)    {        searchf(i+1,size,wall,record);        change(wall+size+2+i,size);        *(record+(size+2)+i)=1;        searchf(i+1,size,wall,record);        change(wall+size+2+i,size);        *(record+(size+2)+i)=0;    }    else        paint(wall,size,record);}void paint(int*wall,int n,int*record){
    int flag=0,i,j;    for(i=1;i<n;i++)    {        for(j=1;j<n+1;j++)        {            if(*(wall+i*(n+2)+j)==0)            {                change(wall+(i+1)*(n+2)+j,n);                *(record+(i+1)*(n+2)+j)=1;                nowtimes++;            }        }    }    for(i=1;i<n+1;i++)    {        flag+=*(wall+n*(n+2)+i);        nowtimes+=*(record+(n+2)+i);    }    if(flag==n&&nowtimes<mintimes)        mintimes=nowtimes;    for(i=2;i<=n;i++)    {        for(j=1;j<n+1;j++)        {            if(*(record+i*(n+2)+j)==1)            {                change(wall+i*(n+2)+j,n);                *(record+i*(n+2)+j)=0;            }        }    }    nowtimes=0;}int main(){    int n,i,j;    scanf("%d",&n);    int paint[n+2][n+2],record[n+2][n+2];    for(i=1;i<n+1;i++)        for(j=1;j<n+1;j++)            record[i][j]=0;    char wall[n+2][n+2];    for(i=1;i<n+1;i++)    {        scanf("%s",&wall[i][1]);        for(j=1;j<n+1;j++)            (wall[i][j]=='w')?(paint[i][j]=0):(paint[i][j]=1);    }    searchf(1,n,paint[0],record[0]);    (mintimes>200)?(printf("inf")):(printf("%d",mintimes));    return 0;}
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