poj 2195

#include<algorithm>
#include<stdio.h>
#include<vector>
#include<queue>
#include<string.h>
using namespace std;
const int INF = 1000;
char a[101][101];
typedef pair<int ,int>P ;
struct edge
{
    int to ,cap,cost,rev;
};
int V;
const int maxn = 1000;
vector<edge>g[maxn];
int  h[maxn];
int dist[maxn];
int prevv[maxn],preve[maxn];
int fabs(int x)
{
    return x>0?x:-x;
}
struct node
{
    int x,y;
} nodev[maxn];
node nodeg[maxn];
void add_edge(int from,int to,int cap,int cost)
{
    g[from].push_back((edge)
    {
        to,cap,cost,g[to].size()
    });
    g[to].push_back((edge)
    {
        from,0,-cost,g[from].size()-1
    });
}
int min_cost_flow(int s,int t,int f)
{
    int res = 0;
    fill(h,h+1+V,0);
    while(f>0)
    {
        priority_queue<P,vector<P>,greater<P> >que;
        fill(dist,dist+V+1,INF);
        dist[s] = 0;
        que.push(P(0,s));
        while(!que.empty())
        {
            P p = que.top();
            que.pop();
            int v = p.second;
            if(dist[v]<p.first)
                continue;
            for(int i = 0; i<g[v].size(); i++)
            {
                edge &e = g[v][i];
                if(e.cap>0&&dist[e.to]>dist[v]+e.cost+h[v]-h[e.to])
                {
                    dist[e.to] = dist[v] +e.cost +h[v] - h[e.to];
                    prevv[e.to] = v;
                    preve[e.to] = i;
                    que.push(P(dist[e.to],e.to));
                }
            }
        }
        if(dist[t]==INF)
        {
            return -1;
        }
        for(int v= 0; v<=V; v++)
        {
            h[v]+=dist[v];
        }
        int d = f;
        for(int v = t; v!=s; v=prevv[v])
        {
            d = min(d,g[prevv[v]][preve[v]].cap);
        }
        res+=d*h[t];
        f-=d;
        for(int v = t; v!=s; v=prevv[v])
        {
            edge &e = g[prevv[v]][preve[v]];
            e.cap -=d;
            g[v][e.rev].cap+=d;
        }
    }
    return res;
}
int main()
{
    int n,m;
    while(scanf("%d%d",&n,&m)!=EOF&&m&&n)
    {
        for(int i = 0;i<maxn;i++)
            g[i].clear();
        int cot1 =1;
        int cot2=1;
        for(int i =1 ; i<=n; i++)
        {
            scanf("%s",a[i]+1);
        }
        for(int i = 1; i<=n; i++)
        {
            for(int j = 1; j<=m; j++)
            {
                if(a[i][j]=='m')
                {
                    nodev[cot1].x = i;
                    nodev[cot1].y = j;
                    cot1++;
                }
                else
                {
                    if(a[i][j]=='H')
                    {
                        nodeg[cot2].x=i;
                        nodeg[cot2].y =j;
                        cot2++;
                    }
                }
            }
        }
        cot1--;
        cot2--;
        V = cot1*2+1;
        for(int i = 1; i<=cot1; i++)
        {
            add_edge(0,i,1,0);
        }
        for(int i = 1; i<=cot2; i++)
        {
            add_edge(cot1+i,2*cot1+1,1,0);
        }
        for(int i  = 1; i<=cot1; i++)
            for(int j = 1; j<=cot2; j++)
            {   
                add_edge(i,j+cot1,1,fabs(nodev[i].x-nodeg[j].x)+fabs(nodev[i].y - nodeg[j].y));
            }

        printf("%d\n",min_cost_flow(0, V,cot1));
    }
}