luogu2050 [NOI2012]美食节
修车加强版
边跑边加,有个师傅做到第 i 个(相对他自己而言),就给他加到 i+1 个。
#include <iostream>
#include <cstring>
#include <cstdio>
#include <queue>
using namespace std;
int n, m, p, ss, tt, uu, hea[85005], cnt, tim[45][105], minCost;
int dis[85005], pre[85005], sf[85005], diji[85005];
const int oo=0x3f3f3f3f;
bool vis[85005];
queue<int> d;
int f(int i, int j){
return (i-1)*p+j;
}
struct Edge{
int too, nxt, val, cst;
}edge[3000005];
void add_edge(int fro, int too, int val, int cst){
edge[cnt].nxt = hea[fro];
edge[cnt].too = too;
edge[cnt].val = val;
edge[cnt].cst = cst;
hea[fro] = cnt++;
}
void addEdge(int fro, int too, int val, int cst){
add_edge(fro, too, val, cst);
add_edge(too, fro, 0, -cst);
}
bool spfa(){
memset(dis, 0x3f, sizeof(dis));
memset(pre, -1, sizeof(pre));
d.push(ss);
vis[ss] = true;
dis[ss] = 0;
while(!d.empty()){
int x=d.front();
d.pop();
vis[x] = false;
for(int i=hea[x]; i!=-1; i=edge[i].nxt){
int t=edge[i].too;
if(dis[t]>dis[x]+edge[i].cst && edge[i].val>0){
dis[t] = dis[x] + edge[i].cst;
pre[t] = i;
if(!vis[t]){
vis[t] = true;
d.push(t);
}
}
}
}
return dis[tt]!=oo;
}
void mcmf(){
while(spfa()){
int tmp=oo, qwq;
for(int i=pre[tt]; i!=-1; i=pre[edge[i^1].too])
tmp = min(tmp, edge[i].val);
for(int i=pre[tt]; i!=-1; i=pre[edge[i^1].too]){
edge[i].val -= tmp;
edge[i^1].val += tmp;
minCost += tmp * edge[i].cst;
}
qwq = edge[pre[tt]^1].too;
addEdge(qwq+1, tt, 1, 0);
for(int i=1; i<=n; i++)
addEdge(i, qwq+1, 1, (diji[qwq]+1)*tim[i][sf[qwq]]);
}
}
int main(){
memset(hea, -1, sizeof(hea));
cin>>n>>m;
ss = 0;
for(int i=1; i<=n; i++){
scanf("%d", &uu);
p += uu;
addEdge(ss, i, uu, 0);
}
tt = n + m * p + 1;
for(int i=1; i<=n; i++)
for(int j=1; j<=m; j++){
scanf("%d", &tim[i][j]);
addEdge(i, f(j,1)+n, 1, tim[i][j]);
}
for(int i=1; i<=m; i++)
addEdge(f(i,1)+n, tt, 1, 0);
for(int i=1; i<=m; i++)
for(int j=1; j<=p; j++){
sf[f(i,j)+n] = i;
diji[f(i,j)+n] = j;
}
mcmf();
cout<<minCost<<endl;
return 0;
}
拙いものと思えども、
その手に握る其れこそが、
いつか幻想を生んでいく。