【HDOJ】2853 Assignment

最小费用最大流可解最优解。至于dif如何解，可以把w扩大100倍，如果mission编号和排列P相等则对w+1，然后建立网络流。
对结果取模100可以得到没有改变mission的company数目，用company数目减之可以得到dif.

/* 2853 */
#include <iostream>
#include <string>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <vector>
#include <deque>
#include <algorithm>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstring>
#include <climits>
#include <cctype>
#include <cassert>
#include <functional>
#include <iterator>
#include <iomanip>
using namespace std;
//#pragma comment(linker,"/STACK:102400000,1024000")

#define sti                set<int>
#define stpii            set<pair<int, int> >
#define mpii            map<int,int>
#define vi                vector<int>
#define pii                pair<int,int>
#define vpii            vector<pair<int,int> >
#define rep(i, a, n)     for (int i=a;i<n;++i)
#define per(i, a, n)     for (int i=n-1;i>=a;--i)
#define clr                clear
#define pb                 push_back
#define mp                 make_pair
#define fir                first
#define sec                second
#define all(x)             (x).begin(),(x).end()
#define SZ(x)             ((int)(x).size())
#define lson            l, mid, rt<<1
#define rson            mid+1, r, rt<<1|1

const int INF = 0x1f1f1f1f;
const int maxn = 55;
const int maxv = maxn * 2;
const int maxe = maxv * maxv * 5;
int V[maxe], F[maxe], W[maxe], nxt[maxe];
int head[maxv], dis[maxv], pre[maxv], ID[maxv];
bool visit[maxv];
int M[maxn][maxn], P[maxn];
int s, t, m;

void addEdge(int u, int v, int f, int w) {
    V[m] = v;
    F[m] = f;
    W[m] = w;
    nxt[m] = head[u];
    head[u] = m++;
    
    V[m] = u;
    F[m] = 0;
    W[m] = -w;
    nxt[m] = head[v];
    head[v] = m++;
}

bool bfs() {
    queue<int> Q;
    int u, v, k;
    
    memset(dis, INF, sizeof(dis));
    memset(visit, false, sizeof(visit));
    Q.push(s);
    dis[s] = 0;
    
    while (!Q.empty()) {
        u = Q.front();
        Q.pop();
        visit[u] = false;
        for (k=head[u]; k!=-1; k=nxt[k]) {
            v = V[k];
            if (F[k] && dis[v]>dis[u]+W[k]) {
                dis[v] = dis[u] + W[k];
                ID[v] = k;
                pre[v] = u;
                if (!visit[v]) {
                    visit[v] = true;
                    Q.push(v);
                }
            }
        }
    }
    
    return dis[t]==INF;
}

int MCMF() {
    int ret = 0, tmp;
    int u, v, k;
    
    while (1) {
        if (bfs())
            break;
        
        tmp = INF;
        for (v=t, u=pre[v]; v!=s; v=u, u=pre[v]) {
            k = ID[v];
            tmp = min(F[k], tmp);
        }
        
        for (v=t, u=pre[v]; v!=s; v=u, u=pre[v]) {
            k = ID[v];
            F[k] -= tmp;
            F[k^1] += tmp;
        }
        
        ret += dis[t] * tmp;
    }
    
    return ret;
}


int main() {
    ios::sync_with_stdio(false);
    #ifndef ONLINE_JUDGE
        freopen("data.in", "r", stdin);
        freopen("data.out", "w", stdout);
    #endif
    
    int r, c;
    int ans, tot, tmp, dif;
    
    while (scanf("%d %d", &r, &c) != EOF) {
        
        s = m = 0;
        t = r + c + 1;
        memset(head, -1, sizeof(head));
        
        rep(i, 1, r+1)
            rep(j, 1, c+1)
                scanf("%d", &M[i][j]);
        rep(i, 1, r+1)        
            scanf("%d", &P[i]);
            
        rep(i, 1, r+1)
            addEdge(s, i, 1, 0);
            
        rep(j, 1, c+1)
            addEdge(j+r, t, 1, 0);
        
        tot = 0;
        rep(i, 1, r+1) {
            rep(j, 1, c+1) {
                if (j == P[i]) {
                    tmp = M[i][j] * 100 + 1;
                } else {
                    tmp = M[i][j] * 100;
                }
                addEdge(i, j+r, 1, -tmp);
            }
            tot += M[i][P[i]];
        }
        
        tmp = -MCMF();
        ans = tmp/100 - tot;
        #ifndef ONLINE_JUDGE
            printf("tot = %d, MCMF = %d
", tot, tmp);
        #endif
        dif = r - tmp%100;
        printf("%d %d
", dif, ans);
    }
    
    #ifndef ONLINE_JUDGE
        printf("time = %d.
", (int)clock());
    #endif
    
    return 0;
}