D - Deliver the Cake(未解決問題
https://vjudge.net/contest/386568#problem/D
It is Zhang3's birthday! Zhang3 has bought a birthday cake and now it's time to take it home.There arennvillages, labeled1,2,…,n1,2,…,n. There aremmbidirectional roads, theithithof which connects villageaiai,bibiand it isdidimeter(s) long.
The bakery locates at village
Some villages are LEFT. When Zhang3 is at a LEFT village, she must carry the cake with her left hand at the moment. In the same way, some other villages are RIGHT, she must carry with her right hand when she's at these villages. The rest villages are called MIDDLE. There's no special rules at MIDDLE villages.
Zhang3 can start and finish with any hand carrying the cake. However, ifssorttis not MIDDLE, their special rules must be followed.
Please help Zhang3 find a way to take the cake home, with the minimum amount of spent time.
InputThe first line of the input gives the number of test cases,T(1≤T≤100)T(1≤T≤100).TTtest cases follow.
For each test case, the first line contains five integersn,m,s,t,x(1≤n≤105,1≤m≤2×105,1≤x≤109)n,m,s,t,x(1≤n≤105,1≤m≤2×105,1≤x≤109), representing the number of villages, the number of roads, the bakery's location, home's location, and the time spent for each switching.
The next line contains a string of lengthnn, describing the type of each village. Theithithcharacter is eitherLLrepresenting villageiiis LEFT, orMMrepresenting MIDDLE, orRRrepresenting RIGHT.
Finally,mmlines follow, theithithof which contains three integersai,bi,di(1≤di≤109)ai,bi,di(1≤di≤109), denoting a road connecting villageaiaiandbibiof lengthdidi.
It is guaranteed thatttcan be reached fromss.
The sum ofnnin all test cases doesn't exceed2×1052×105. The sum ofmmdoesn't exceed4×1054×105.
OutputFor each test case, print a line with an integer, representing the minimum amount of spent time (in seconds).
Sample Input
1 3 3 1 3 100 LRM 1 2 10 2 3 10 1 3 100
Sample Output
100
Sponsor
參考程式碼:https://www.cnblogs.com/chuliyou/p/13416544.html
思路:
區別左手右手
分成兩個方向用dijsktra?(未解決
附草稿程式碼:
#include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<bitset> #include<cassert> #include<cctype> #include<cmath> #include<cstdlib> #include<ctime> #include<deque> #include<iomanip> #include<list> #include<map> #include<queue> #include<set> #include<stack> #include<vector> #include <vector> #include <iterator> #include <utility> #include <sstream> #include <limits> #include <numeric> #include <functional> using namespace std; #define gc getchar() #define mem(a) memset(a,0,sizeof(a)) //#define sort(a,n,int) sort(a,a+n,less<int>()) #define ios ios::sync_with_stdio(false);cin.tie(0);cout.tie(0); typedef long long ll; typedef unsigned long long ull; typedef long double ld; typedef pair<int,int> pii; typedef char ch; typedef double db; const double PI=acos(-1.0); const double eps=1e-6; const int inf=0x3f3f3f3f; const int maxn=1e5+10; const int maxm=100+10; const int N=4e5+10; const int mod=1e9+7; int n, m, s, t, xx; struct Node { int head; int ver; int edge; int Next; }line[N*2]; bool v[N*2]; long long d[N*2]; int hand[N*2]; int tot = 0; priority_queue <pair<long long , int> >q; void add(int x , int y , int z) { tot += 1; line[tot].ver = y; line[tot].edge = z; line[tot].Next = line[x].head; line[x].head = tot; } long long dijkstra(int s, int t) { long long ans = 1e18; for(int i = 1; i<=2*n;i++) { d[i] = 1e18; } memset(v , 0 , sizeof(v)); d[s] = 0; q.push(make_pair(0 , s)); int i = 0 , j = 0; while(q.size()) { int x = q.top().second; q.pop(); if(v[x]) { continue; } v[x] = 1; for(i = line[x].head;i != 0; i=line[i].Next) { int y = line[i].ver , z = line[i].edge; if(hand[x] != hand[y]) { z += xx;//是否要換手 }if(d[y] > d[x]+z) { d[y] = d[x] + 1ll*z; q.push(make_pair(-d[y] , y)); } } } return min(d[t] , d[t + n]); } signed main() { int T = 0; cin >> T; while(T--) { tot = 0; for(int i = 1;i<=2*n;i++) { line[i].head = 0; } cin >> n >> m >> s >> t >> xx; string S; cin >> s; for(int i = 0;i<S.size();i++) { if(S[i] == 'L') { hand[i+1] = 0; hand[i+1+n] = 0; } if(S[i] == 'M') { hand[i+1] = 0; hand[i+1+n] = 1; } if(S[i] == 'R') { hand[i+1] = 1; hand[i+1+n] = 1; } } for(int i = 1; i <= m; i++) { int u = 0 , v = 0 , w = 0; cin >> u >> v >> w; add(u , v , w); add(v , u , w); add(u+n , v , w); add(v , u+n , w); add(u , v+n , w); add(v+n , u , w); add(u+n , v+n , w); add(v+n , u+n , w); } cout << min(dijkstra(s,t) , dijkstra(s+n, t)) <<endl; } return 0; }