I Interval（区间变化限制）

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
const int M=5e5+5;;
const int inf=0x3f3f3f3f;
const ll INF=1e18;
ll dis[M];
bool vis[M];
int id[505][505];
struct node{
    int v;
    ll c;
    node(int V=0,ll C=0):v(V),c(C){}
    bool operator <(const node &b)const  {
        return c>b.c;
    }
};
struct Edge{
    int v;
    ll cost;
    Edge(int V=0,ll Cost=0):v(V),cost(Cost){}
};
vector<Edge>g[M];
void addedge(int u,int v,ll w){
    g[u].push_back(Edge(v,w));
    g[v].push_back(Edge(u,w));
}
void dij(int st,int n){
    priority_queue<node>que;
    for(int i=1;i<=n;i++)
        dis[i]=INF;
    while(!que.empty())que.pop();
    dis[st]=0;
    que.push(node(st,0));
    while(!que.empty()){
        node tmp=que.top();
        que.pop();
        int u=tmp.v;
        if(vis[u])
            continue;
        vis[u]=true;
        for(auto it:g[u]){
            int v=it.v;
            ll cost=it.cost;
            if(!vis[v]&&dis[v]>dis[u]+cost){
                dis[v]=dis[u]+cost;
                que.push(node(v,dis[v]));
            }
        }
    }
}

int main(){
    int n,m,tot=0;
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n-1;i++)
        for(int j=i;j<=n-1;j++)
            id[i][j]=++tot;
    int s=++tot,t=++tot;
    for(int i=1;i<=m;i++){
        int l,r;
        ll w;
        char op[2];
        scanf("%d%d%s%lld",&l,&r,op,&w);
        if(op[0]==‘L‘){
            if(r==n)
                addedge(id[l][r-1],t,w);
            else
                addedge(id[l][r],id[l][r-1],w);
        }
        else{
            if(l==1)
                addedge(id[l][r-1],s,w);
            else
                addedge(id[l][r-1],id[l-1][r-1],w);
        }
    }
    dij(s,t);
    if(dis[t]>=INF)
        puts("-1");
    else
        printf("%lld\n",dis[t]);
    return 0;
}