# P4014 Allocation Problem [Network Flow 24 Minimum/Large Cost Maximum Flow]

### Portal

Bullshit: It should be a template topic for maximum streaming cost flow

Solution ideas: Maximum and minimum benefits under the condition that everyone has a job.Minimum Return: Cost Flow Template.Maximum profit: Reverse the profit, run the board once, the answer is equal to the minimum cost reversal.
A Super Source - > Everyone (Upper Stream Limit 1, Cost 0)
Person->Work (Upper stream Limit 1, Cost (Minimum Income Cij, Maximum Income -Cij))
Work->Super Sink (Upper Flow Limit 1, Cost 0)

Code:

```///#include<bits/stdc++.h>
///#include<unordered_map>
///#include<unordered_set>
#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<string>
#include<cmath>
#include<queue>
#include<bitset>
#include<set>
#include<stack>
#include<map>
#include<list>
#include<new>
#include<vector>

#define MT(a, b) memset(a,b,sizeof(a)
#define lowbit(x) (x&(-x))
using namespace std;
typedef long long ll;
const double pai = acos(-1.0);
const double E = 2.718281828459;
const ll mod = 1e9 + 7;
const int INF = 0x3f3f3f3f;
const double esp = 1e-6;
const int maxn = 5e2 + 5;

int n, Sta, End;
int inque[maxn], dis[maxn], pre[maxn], flow[maxn];
int maps[105][105];
struct node {
int e, c, f, p;

void add_edge(int s, int e, int c, int f) {
}

bool spfa() {
for (int i = 0; i <= n * 2 + 1; i++) {
inque[i] = 0;
flow[i] = dis[i] = INF;
pre[i] = -1;
}
inque[Sta] = 1, dis[Sta] = 0;
queue<int> q;
q.push(Sta);
while (!q.empty()) {
int s = q.front();
q.pop();
inque[s] = 0;
for (int i = head[s], e, c, f; ~i; i = load[i].p) {
if (f > 0 && dis[e] > dis[s] + c) {
dis[e] = dis[s] + c;
flow[e] = min(flow[s], f);
pre[e] = i;
if (!inque[e]) {
inque[e] = 1;
q.push(e);
}
}
}
}
return dis[End] != INF;
}

void init() {
sign = -1;
}

int main() {
init();
int  minans = 0, maxans = 0;
scanf("%d", &n);
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++)
scanf("%d", &maps[i][j]);
}

Sta = 0, End = n * 2 + 1;
///Minimum income
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++) {
add_edge(i, n + j, maps[i][j], 1);
add_edge(n + j, i, -maps[i][j], 0);
}
add_edge(n + i, End, 0, 1);
add_edge(End, n + i, 0, 0);
}
while (spfa()) {
int f = flow[End];
for (int i = pre[End]; i!=-1; i = pre[load[i ^ 1].e]) {
}
}
///Maximum Revenue
init();
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++) {
add_edge(i, n + j, -maps[i][j] ,1);
add_edge(n + j, i, maps[i][j] ,0);
}
}
for (int j = 1; j <= n; j++) {
add_edge(n + j, End, 0, 1);
add_edge(End, n + j, 0, 0);
}
while (spfa()) {
int f = flow[End];
for (int i = pre[End]; i!=-1; i = pre[load[i ^ 1].e]) {