HDU 1874 Spfa/bellmanford/dijkstra/floyd

This problem as a template problem, the solution is many ...

Recently around the people are on the map, I feel good spicy chicken, will only follow the follow-up study.

Only SPFA for the moment.

SPFA (adjacency table version.) Can also be written as a pro-matrix map, but the topic may give parallel edges, so pay attention to find the smallest side of the storage, but also to determine whether a point more than once into the queue) honestly think that SPFA seems to be just a queue optimized search the same.

1#include <stdio.h>2#include <algorithm>3#include <iostream>4#include <string.h>5#include <utility>6#include <vector>7#include <queue>8 #defineMAXX 100109 using namespacestd;Ten  One Const intN = -; A Const intINF =0x3f3f3f3f; -  -  thetypedefstructSion - { -     intdis; -     intNXP; + }sion; -  + intDic[n]; A BOOLVis[n]; atVector<sion>Li[n]; -  -  - intSPFA (int&s,int&t) - { -queue<int>Q; in Q.push (s); -Vis[s] =1; toDic[s] =0; +      while(!q.empty ()) -     { the         intPre =Q.front (); * Q.pop (); $          for(inti =0; I < li[pre].size (); i++)Panax Notoginseng         { -            //cout << Dic[li[pre][i].nxp] << "~"; the             if(Dic[li[pre][i].nxp] > Dic[pre] +Li[pre][i].dis) +             { ADIC[LI[PRE][I].NXP] = Dic[pre] +Li[pre][i].dis; the Q.push (LI[PRE][I].NXP); +                    //cout << DIC[LI[PRE][I].NXP] << "!"; -             } $         } $  -     } -     returnDic[t]; the } - Wuyi voidInit () the { -memset (Vis,false,sizeof(Vis)); Wumemset (Dic,inf,sizeof(DIC)); -      for(inti =0; i < N; i++) About li[i].clear (); $     return ; - } -  - intMain () A { +     intN, M; the     ints, t; -      while(Cin >> N >>m) $     { the init (); the sion A; the         intx; the          for(inti =0; I < m; i++) -         { inscanf"%d%d%d", &x, &AMP;A.NXP, &A.dis); the Li[x].push_back (a); the             inttemp =A.nxp; AboutA.NXP =x; the Li[temp].push_back (a); the         } thescanf"%d%d", &s, &t); +         inty =SPFA (S, t); -         if(Y >=INF) the         {Bayiprintf"-1\n"); the         } the         Elseprintf"%d\n", y); -     } -}

HDU 1874 Spfa/bellmanford/dijkstra/floyd