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HDU 3395 Special Fish

2019年04月07日 ⁄ 综合 ⁄ 共 1430字 ⁄ 字号 评论关闭

7月冒泡第4题。

大意明白后很好写,注意初始化W的值。

#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <string>
#include <cstring>
#include <cmath>
#include <vector>
#include <queue>
#include <algorithm>
#include <map>
using namespace std;

const int maxn = 110;
const int INF = 0x3f3f3f3f;

int n, m;

int W[maxn][maxn];
int Lx[maxn], Ly[maxn];

int Left[maxn];
bool S[maxn], T[maxn];

bool match(int i)
{
    S[i] = 1;
    for(int j = 1; j <= n; j++) if(Lx[i]+Ly[j] == W[i][j] && !T[j])
    {
        T[j] = 1;
        if(!Left[j] || match(Left[j]))
        {
            Left[j] = i;
            return 1;
        }
    }
    return 0;
}

void update()
{
    int a = INF;
    for(int i = 1; i <= n; i++) if(S[i])
    for(int j = 1; j <= n; j++) if(!T[j])
        a = min(a, Lx[i]+Ly[j]-W[i][j]);
        
    for(int i = 1; i <= n; i++)
    {
        if(S[i]) Lx[i] -= a;
        if(T[i]) Ly[i] += a;
    }
}

void KM()
{
    for(int i = 1; i <= n; i++)
    {
        Left[i] = Lx[i] = Ly[i] = 0;
        for(int j = 1; j <= n; j++)
            Lx[i] = max(Lx[i], W[i][j]);
    }
    for(int i = 1; i <= n; i++)
    {
        for(;;)
        {
            for(int j = 1; j <= n; j++) S[j] = T[j] = 0;
            if(match(i)) break; else update();
        }
    }
}

inline void readint(int &x)
{
    char c;
    c = getchar();
    while(!isdigit(c)) c = getchar();
    
    x = 0;
    while(isdigit(c)) x = x*10+c-'0', c = getchar();
}

inline void writeint(int x)
{
    if(x > 9) writeint(x/10);
    putchar(x%10+'0');
}

int val[maxn];
char s[110][110];

void read_case()
{
	m = n;
	
	for(int i = 1; i <= n; i++) readint(val[i]);
	for(int i = 1; i <= n; i++) scanf("%s", s[i]+1);
}

void build()
{
	for(int i = 1; i <= n; i++)
	{
		for(int j = 1; j <= n; j++)
		{
			if(s[i][j] == '1')
			{
				W[i][j] = val[i]^val[j];
			}
		}
	}
}

void solve()
{
	memset(W, 0, sizeof(W));
	read_case();
	
	build();
	KM();
	
	int ans = 0;
	for(int i = 1; i <= n; i++) if(Left[i]) ans += W[Left[i]][i];
	writeint(ans), puts("");
}

int main()
{
	for(readint(n); n; readint(n))
	{
		solve();
	}
	return 0;
}

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