ZOJ 1654

来源：互联网发布：为啥淘宝提交不了订单编辑：程序博客网时间：2024/05/16 17:17

二部图匹配问题，思路大致就是先将空地按照行进行标号，之后再按照列标号，最后把重叠的部分连一条边，在用匈牙利求出最大的匹配数就可以了，主要是建图这一个步骤，图建好了就很简单了;以下是代码：

话说这次的代码是不是很优美呢。。。。。。

#include<stdio.h>#include<algorithm>#include<string.h>#include<iostream>#define MAXN 51using namespace std;char inputmap[MAXN][MAXN];int grap_x[MAXN][MAXN],grap_y[MAXN][MAXN];int match_x[MAXN*MAXN],match_y[MAXN*MAXN];int use[MAXN*MAXN],have_path[MAXN*MAXN][MAXN*MAXN];int n,m;int num_x,num_y;void init(){    memset(grap_x,0,sizeof(grap_x));    memset(grap_y,0,sizeof(grap_y));    memset(have_path,0,sizeof(have_path));    return ;}void build_grap(){    for(int i = 0; i < m; i++)    {        for(int j = 0; j < n; j++)        {            if(grap_x[i][j] != 0 && grap_y[i][j] != 0)            {                have_path[grap_x[i][j]][grap_y[i][j]] = 1;            }        }    }    return ;}int find_path(int u){    for(int v = 1; v <= num_y; v++)    {        if(have_path[u][v] == 1 && !use[v])        {            use[v] = 1;            if(match_y[v] == -1 || find_path(match_y[v]))            {                match_y[v] = u;                match_x[u] = v;                return 1;            }        }    }    return 0;}int maxmatch(){    int res = 0;    memset(match_x,-1,sizeof(match_x));    memset(match_y,-1,sizeof(match_y));    for(int i = 1; i <= num_x; i++)    {        if(match_x[i] == -1)        {            memset(use,0,sizeof(use));            res+= find_path(i);        }    }    return res;}int main(){    int t;    int num_case=1;    int ans,judge;    scanf("%d", &t);    while(t--)    {        scanf("%d%d", &m, &n);        for(int i = 0; i < m; i++) scanf("%s", inputmap[i]);        init();        num_x=0;        for(int i = 0; i < m; i++)        {            judge = 0;            for(int j = 0; j < n; j++)            {                if(inputmap[i][j] == 'o')                {                    if(!judge) num_x++;                    grap_x[i][j] = num_x;                    judge = 1;                }                if(inputmap[i][j] == '#')                {                    judge = 0;                }             }        }        num_y=0;        for(int j = 0; j < n; j++)        {            judge = 0;            for(int i = 0; i < m; i++)            {                if(inputmap[i][j] == 'o')                {                    if(!judge) num_y++;                    grap_y[i][j] = num_y;                    judge = 1;                }                if(inputmap[i][j] == '#')                {                    judge = 0;                }            }        }        build_grap();        ans = maxmatch();        printf("Case :%d\n",num_case++);        printf("%d\n",ans);    }    return 0;}

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