可能再也用不到了吧，今天整理电脑文件看到的，作为图论选手，留个纪念，
//原图： 对于pi，拆点xi,yi s->S,[m,m],0 S->xi,[0,inf],0 yi->t,[0,inf],0 xi->yi,[vi,vi],0 对于有航线的pi和pj，yi->xj,[0,inf],cost
//这样就建好了原图 那么有源汇有上下界的费用流的改造方法： 首先建立附加源汇ss,tt 对于原图里有的一条边x->y,[l,r],cost，变成x->y,r-l,cost 每一个点的权di定义为所有流入这个点的边的下界和-所有流出这个点的边的下界和 对于一个点i，若di>0，ss->i,di,0；若di<0，i->tt,-di,0 连边t->s,inf,0 然后对ss,tt做最小费用最大流 最终的费用为（网络流中计算的费用+原图中有费用的边的下界*这条边的费用）
//代码
#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<queue>
using namespace std;
#define N 40005
#define inf 2000000000
int n,m,x,mincost,s,t,S,ss,tt;
int tot,point[N],nxt[N],v[N],remain[N],c[N];
int dis[N],last[N],d[N];
bool vis[N];
queue <int> q;
void addedge(int x,int y,int cap,int z) {
++tot;
nxt[tot]=point[x];
point[x]=tot;
v[tot]=y;
remain[tot]=cap;
c[tot]=z;
++tot;
nxt[tot]=point[y];
point[y]=tot;
v[tot]=x;
remain[tot]=0;
c[tot]=-z;
}
int addflow(int s,int t) {
int now=t,ans=inf;
while (now!=s) {
ans=min(ans,remain[last[now]]);
now=v[last[now]^1];
}
now=t;
while (now!=s) {
remain[last[now]]-=ans;
remain[last[now]^1]+=ans;
now=v[last[now]^1];
}
return ans;
}
bool spfa(int s,int t) {
memset(dis,127,sizeof(dis));
dis[s]=0;
memset(vis,0,sizeof(vis));
vis[s]=1;
while (!q.empty()) q.pop();
q.push(s);
while (!q.empty()) {
int now=q.front();
q.pop();
vis[now]=0;
for (int i=point[now]; i!=-1; i=nxt[i]) if (dis[v[i]]>dis[now]+c[i]&&remain[i]) {
dis[v[i]]=dis[now]+c[i];
last[v[i]]=i;
if (!vis[v[i]]) {
vis[v[i]]=1;
q.push(v[i]);
}
}
}
if (dis[t]>inf) return 0;
int flow=addflow(s,t);
mincost+=flow*dis[t];
return 1;
}
int main() {
tot=-1;
memset(point,-1,sizeof(point));
scanf("%d%d",&n,&m);
S=n+n+1,s=S+1,t=s+1;
ss=t+1,tt=ss+1;
d[s]-=m,d[S]+=m;
for (int i=1; i<=n; ++i) {
scanf("%d",&x);
addedge(S,i,inf,0);
addedge(n+i,t,inf,0);
d[i]-=x,d[n+i]+=x;
}
for (int i=1; i<n; ++i) for (int j=i+1; j<=n; ++j) {
scanf("%d",&x);
if (x==-1) continue;
addedge(n+i,j,inf,x);
}
for (int i=1; i<=t; ++i) {
if (d[i]>0) addedge(ss,i,d[i],0);
if (d[i]<0) addedge(i,tt,-d[i],0);
}
addedge(t,s,inf,0);
while (spfa(ss,tt));
PRintf("%d\n",mincost);
}
#include <queue>
#include <cstdio>
#include <cstring>
#include <iostream>
using namespace std;
#define INF 1e9
const int N=30000;
int tot=-1,nxt[N],point[N],remind[N],c[N],last[N],dis[N],v[N],mincost,d[N];
bool vis[N];
void addline(int x,int y,int cap,int cc) {
++tot;
nxt[tot]=point[x];
point[x]=tot;
v[tot]=y;
remind[tot]=cap;
c[tot]=cc;
++tot;
nxt[tot]=point[y];
point[y]=tot;
v[tot]=x;
remind[tot]=0;
c[tot]=-cc;
}
int addflow(int s,int t) {
int now=t,ans=INF;
while (now!=s) {
ans=min(ans,remind[last[now]]);
now=v[last[now]^1];
}
now=t;
while (now!=s) {
remind[last[now]]-=ans;
remind[last[now]^1]+=ans;
now=v[last[now]^1];
}
return ans;
}
bool spfa(int s,int t) {
queue<int>q;
q.push(s);
memset(dis,0x7f,sizeof(dis));
memset(vis,0,sizeof(vis));
dis[s]=0;
while (!q.empty()) {
int x=q.front();
q.pop();
vis[x]=0;
for (int i=point[x]; i!=-1; i=nxt[i])
if (dis[v[i]]>dis[x]+c[i] && remind[i]) {
last[v[i]]=i;
dis[v[i]]=dis[x]+c[i];
if (!vis[v[i]]) vis[v[i]]=1,q.push(v[i]);
}
}
if (dis[t]>INF) return 0;
int flow=addflow(s,t);
mincost+=flow*dis[t];
return 1;
}
int main() {
memset(point,-1,sizeof(point));
int x,n,m;
scanf("%d%d",&n,&m);
int s=n*2+1,S=s+1,t=S+1,ss=t+1,tt=ss+1;
addline(s,S,m,0);
// d[s]-=m; d[S]+=m;
for (int i=1; i<=n; i++) addline(S,i,INF,0),addline(i+n,t,INF,0);
for (int i=1; i<=n; i++) scanf("%d",&x),d[i]-=x,d[i+n]+=x;
for (int i=1; i<n; i++)
for (int j=i+1; j<=n; j++) {
scanf("%d",&x);
if (x!=-1) addline(i+n,j,INF,x);
}
for (int i=1; i<=n; i++) addline(i+n,t,INF,0);
for (int i=1; i<=t; i++) {
if (d[i]>0) addline(ss,i,d[i],0);
if (d[i]<0) addline(i,tt,-d[i],0);
}
addline(t,s,INF,0);
while (spfa(ss,tt));
printf("%d",mincost);
}