HDU-1533 Going Home

KM模版题。

#include <cstdlib>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <fstream>
#include <iostream>
#define rep(i, l, r) for(int i=l; i<=r; i++)
#define N 123
#define MAX 1<<30
#define ll long long
#define clr(x, c) memset(x, c, sizeof(x))
using namespace std;
int read()
{
	int x=0, f=1; char ch=getchar();
	while (ch<‘0‘ || ch>‘9‘) { if (ch==‘-‘) f=-1; ch=getchar(); }
	while (ch>=‘0‘ && ch<=‘9‘) { x=x*10+ch-‘0‘; ch=getchar(); }
	return x*f;
}

struct point{int x, y;} wx[N], wy[N];
int n, m, nx, ny, v[N][N], l[N], st[N], lx[N], ly[N];
bool vx[N], vy[N];
char s[N];

bool Find(int x)
{
	vx[x]=1;
	rep(y, 1, ny) if (!vy[y])
	{
		int a=lx[x]+ly[y]-v[x][y];
		if (!a)
		{
			vy[y]=1; if (!l[y] || Find(l[y])) { l[y]=x; return true; }
		}
		else st[y]=min(st[y], a);
	}
	return false;
}

int KM()
{
	clr(ly, 0); clr(l, 0);
	rep(i, 1, nx) lx[i]=-MAX;
	rep(i, 1, nx) rep(j, 1, ny) if (v[i][j]>lx[i]) lx[i]=v[i][j];
	rep(i, 1, nx)
	{
		rep(j, 1, ny) st[j]=MAX;
		while (1)
		{
			clr(vx, 0); clr(vy, 0);
			if (Find(i)) break;
			int a=MAX; rep(j, 1, ny) if (!vy[j] && a>st[j]) a=st[j];
			rep(j, 1, nx) if (vx[j]) lx[j]-=a;
			rep(j, 1, ny) if (vy[j]) ly[j]+=a; else st[j]-=a;
		}
	}
	int ans=0;
	rep(i, 1, ny) ans+=v[l[i]][i];
	return ans;
}

int main()
{
	while (~scanf("%d%d", &n, &m) && (n||m))
	{
		nx=ny=0;
		rep(i, 1, n)
		{
			scanf("%s", s);
			rep(j, 1, m)
				if (s[j-1]==‘m‘) nx++, wx[nx].x=i, wx[nx].y=j;
				else if (s[j-1]==‘H‘) ny++, wy[ny].x=i, wy[ny].y=j;
		}
		rep(i, 1, nx) rep(j, 1, ny) v[i][j]=-(abs(wx[i].x-wy[j].x)+abs(wx[i].y-wy[j].y));
		printf("%d\n", -KM());
	}
	return 0;
}