[ZJOI2006]物流运输-SPFA-DP
先埋坑,
#include<iostream> #include<stdio.h> #include<string.h> #include<algorithm> #include<vector> #include<queue> using namespace std; const int inf = 2e9; struct node{ int u; int v; int w; int next; }edge[10005]; int n,m,k,e; int cnt; int head[105]; int dp[105]; int cost[105][105]; bool vis[105]; int a[105][105]; bool flag[105]; int d[105]; int num=0; void addedge(int x,int y,int w){ num++; edge[num].v=y; edge[num].w=w; edge[num].next=head[x]; head[x]=num; } int sbfa(){ memset(d,0x7f,sizeof(d)); memset(vis,0,sizeof(vis)); d[1]=0; vis[1]=1; queue<int>que; while(!que.empty()){ que.pop(); } que.push(1); while(!que.empty()){ int s=que.front(); que.pop(); vis[s]=0; for (int i=head[s];i;i=edge[i].next){ // cout<<"--"<<endl; if (d[edge[i].v]>d[s]+edge[i].w && !flag[edge[i].v]){ d[edge[i].v]=d[s]+edge[i].w; if (!vis[edge[i].v]){ vis[edge[i].v]=1; que.push(edge[i].v); } } } } return d[m]; } int main(){ int x,y,z; while(~scanf("%d%d%d%d",&n,&m,&k,&e)){ num=0; for (int i=1;i<=e;i++){ scanf("%d%d%d",&x,&y,&z); addedge(x,y,z); addedge(y,x,z); } scanf("%d",&cnt); int p,tmp1,tmp2; for (int i=1;i<=cnt;i++){ scanf("%d%d%d",&p,&tmp1,&tmp2); for (int j=tmp1;j<=tmp2;j++){ a[p][j]=1; } } for (int i=1;i<=n;i++){ for (int j=i;j<=n;j++){ memset(flag,0,sizeof(flag)); for (int k=1;k<=m;k++) for (int l=i;l<=j;l++) flag[k]|=a[k][l]; cost[i][j]=sbfa(); } } for (int i=1;i<=n;i++) for (int j=i;j<=n;j++){ if (cost[i][j]<inf)cost[i][j]*=(j-i+1); } memset(dp,0x7f,sizeof(dp)); for (int i=1;i<=n;i++){ dp[i]=cost[1][i]; } for (int i=2;i<=n;i++){ for (int j=1;j<i;j++){ dp[i]=min(dp[i],dp[j]+cost[j+1][i]+k); } } printf("%d\n",dp[n]); } return 0; }
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