2018焦作区域赛网络赛F: Modular Production Line（最大费用流）

传送门
给出了1e5个点，但是因为最多200条边，也就是最多用到400个点，所用先离散化，然后建图。
建图：
1.对权值为w的区间[u,v],加边id(u)->id(v+1),容量为1,费用为-w;
2.对所有相邻的点加边id(i)->id(i+1),容量为正无穷,费用为0;
3.建立源点汇点,由源点s向最左侧的点加边,容量为K,费用为0,由最右侧的点向汇点加边,容量为K,费用为0
4.跑出最大流后,最小费用取绝对值就是能获得的最大权

#include
#define int long long
using namespace std;
const int maxn = 1e4+10;
const int maxm = 1e5+10;
const int inf = 0x3f3f3f3f;
struct Edge
{
    int to,next,cap,flow,cost;
}edge[maxm];
int head[maxn],tol,pre[maxn],dis[maxn];
bool vis[maxn];
void Init(int n)
{
    tol = 0;
    memset(head,-1, sizeof(head));
}
void add_edge(int u,int v,int cap,int cost)
{
    edge[tol].to = v;
    edge[tol].cap = cap;
    edge[tol].cost = cost;
    edge[tol].flow = 0;
    edge[tol].next = head[u];
    head[u] = tol++;

    edge[tol].to = u;
    edge[tol].cap = 0;
    edge[tol].cost = -cost;
    edge[tol].flow = 0;
    edge[tol].next = head[v];
    head[v] = tol++;
}
bool Spfa(int s,int t)
{
    queueq;
    while(!q.empty())
        q.pop();
    memset(dis,inf, sizeof(dis));
    memset(vis,false, sizeof(vis));
    memset(pre,-1, sizeof(pre));
    dis[s] = 0;
    vis[s] = true;
    q.push(s);
    while(!q.empty())
    {
        int u = q.front();
        q.pop();
        vis[u] = false;
        for(int i = head[u];i != -1;i = edge[i].next)
        {
            int v = edge[i].to;
            if(edge[i].cap > edge[i].flow && dis[v] > dis[u] + edge[i].cost)
            {
                dis[v] = dis[u] + edge[i].cost;
                pre[v] = i;
                if(!vis[v])
                {
                    vis[v] = true;
                    q.push(v);
                }
            }
        }
    }
    if(pre[t] == -1)
        return false;
    return true;
}
void minCostmaxFlow(int s,int t)
{
    int flow = 0,cost = 0;
    while(Spfa(s,t))
    {
        int Min = inf;
        for(int i = pre[t];i != -1;i = pre[edge[i^1].to])
        {
            if(Min > edge[i].cap - edge[i].flow)
                Min = edge[i].cap - edge[i].flow;
        }
        for(int i = pre[t];i != -1;i = pre[edge[i^1].to])
        {
            edge[i].flow += Min;
            edge[i^1].flow -= Min;
            cost += edge[i].cost * Min;
        }
        flow += Min;
    }
    printf("%lld\n",-cost);
}
struct node
{
    int u,v,flow;
}f[300];
signed main()
{
    //freopen("in","r",stdin);
    int TT,N,K,M;
    scanf("%lld",&TT);
    while(TT--)
    {
        mapmp;
        mp.clear();
        scanf("%lld%lld%lld",&N,&K,&M);
        for(int i = 1;i <= M; i++)
        {
            scanf("%lld%lld%lld",&f[i].u,&f[i].v,&f[i].flow);
            f[i].v += 1;
            mp[f[i].u] = 1;
            mp[f[i].v] = 1;
        }
        int cnt = 0;
        for(auto it : mp)
        {
            int id = it.first;
            mp[id] = ++cnt;
        }
        Init(cnt);
        int S = 0,T = cnt + 1;
        add_edge(S,1,K,0);
        add_edge(cnt,T,K,0);
        for(int i = 1;i < cnt; i++)
            add_edge(i,i + 1,inf,0);
        for(int i = 1;i <= M; i++)
            add_edge(mp[f[i].u],mp[f[i].v],1,-f[i].flow);
        minCostmaxFlow(S,T);
    }
    return 0;
}