主要是今天写的时候发现最大权匹配不一定是最大匹配,所以要给每个s侧的点一条直接连向t的边,表示这个点可以不匹配.
#include<bits/stdc++.h>
#define int long long
using namespace std;
const int maxn=1500005;
inline int read(){
char c=getchar();int t=0,f=1;
while(!isdigit(c)){if(c=='-')f=-1;c=getchar();}
while(isdigit(c)){t=(t<<3)+(t<<1)+(c^48);c=getchar();}
return t*f;
}
struct edge{
int v,p,w,c;
}e[maxn<<1];
int h[2005],cnt=1;
inline void add(int a,int b,int c,int d){
e[++cnt].p=h[a];
e[cnt].v=b;
e[cnt].w=c;
e[cnt].c=d;
h[a]=cnt;
}
int n,m,k,s,t;
const int inf=1e18;
int vis[2005],dis[2005],inq[2005];
int bfs(){
queue<int> q;
while(!q.empty())q.pop();
for(int i=1;i<=t;i++){dis[i]=inf;inq[i]=0;}
dis[s]=0;
while(!q.empty())q.pop();
q.push(s);
while(!q.empty()){
int u=q.front();q.pop();inq[u]=0;
for(int i=h[u];i;i=e[i].p){
int v=e[i].v;
//printf("%lld %lld %lld\n",v,dis[v],dis[u]+e[i].c);
if(dis[v]>dis[u]+e[i].c&&e[i].w){
dis[v]=dis[u]+e[i].c;
if(!inq[v]){
q.push(v);
inq[v]=1;
}
}
}
}
return dis[t]!=inf;
}
int ht[2005],cost;
int dfs(int u,int rest){
if((u==t)||rest==0)return rest;
vis[u]=1;
int tot=0;
for(int &i=ht[u];i;i=e[i].p){
int v=e[i].v;
if(dis[v]==dis[u]+e[i].c&&e[i].w&&((!vis[v])||(v==t))){
int di=dfs(v,min(rest,e[i].w));
rest-=di;tot+=di;
e[i].w-=di;e[i^1].w+=di;cost+=di*e[i].c;
if(rest==0)break;
}
}
return tot;
}
void dinic(){
while(bfs()){
vis[t]=1;
while(vis[t]){
for(int i=1;i<=t;i++){vis[i]=0;ht[i]=h[i];}
int tmp=dfs(s,inf);
// printf("%lld\n",tmp);
}
}
}
void print(int x){
if(x==0){puts("0");return ;}
char s[55];
memset(s,0,sizeof(s));
int cnt=0;
while(x){
s[++cnt]=x%10+'0';x/=10;
}
for(int i=cnt;i>=1;i--)printf("%c",s[i]);
puts("");
}
signed main(){
//freopen("6.in","r",stdin);
//freopen("6.out","w",stdout);
n=read(),m=read();k=read();
for(int i=1;i<=k;i++){
int a=read(),b=read(),c=-read();
add(a,b+n,1,c);
add(b+n,a,0,-c);
}
s=n+m+1,t=n+m+2;
for(int i=1;i<=n;i++){
add(s,i,1,0);add(i,s,0,0);
add(i,t,1,0);add(t,i,0,0);
}
for(int i=1;i<=m;i++){
add(i+n,t,1,0);add(t,i+n,0,0);
}
dinic();
cost=cost*-1;
print(cost);
return 0;
}