Hdu 2544 hdu 1874 Dijkstra Template questions

HDU 2544

Find the shortest 1 point n

Sample Input
2 1//Node number edge
1 2 3//u v W
3 3
1 2 5
2 3 5
3 1 2
0 0

Sample Output
3
2

1# include <iostream>2# include <cstdio>3# include <cstring>4# include <algorithm>5# include <cmath>6# define LLLong Long7 using namespacestd;8 9 Const intmaxn= $;Ten Const intinf=0x3f3f3f3f; One intN; A BOOLVIS[MAXN]; - intCOST[MAXN][MAXN]; - intLOWCOST[MAXN]; the intPRE[MAXN]; - voidDijkstra (intBeg) - { -      for(intI=0; i<n;i++) +     { -lowcost[i]=inf;vis[i]=false;p re[i]=-1; +     } Alowcost[beg]=0; at      for(intj=0; j<n;j++) -     { -         intk=-1; -         intmin=INF; -          for(intI=0; i<n;i++) -             if(!vis[i]&&lowcost[i]<Min) in             { -min=Lowcost[i]; tok=i; +             } -             if(k==-1) Break; thevis[k]=true; *              for(intI=0; i<n;i++) $                 if(!vis[i]&&lowcost[k]+cost[k][i]<Lowcost[i])Panax Notoginseng                 { -lowcost[i]=lowcost[k]+Cost[k][i]; thepre[i]=K; +                 } A     } the } +  - intMain () $ { $   //freopen ("In.txt", "R", stdin); -     intm; -      while(SCANF ("%d%d", &n, &m)! =EOF) the     { -         if(n==0&& m==0)Wuyi              Break ; the         intu, V, W; -         intI, J; Wu          for(i =0; I < n; i++) -              for(j =0; J < N; J + +) AboutCOST[I][J] =INF; $           while(m--) -         { -scanf"%d%d%d", &u, &v, &W); -             if(W < Cost[u][v])//prevent heavy edges A             { +COST[U][V] =W; theCost[v][u] =W; -             } $         } theDijkstra (0) ; theprintf"%d\n", lowcost[n-1]) ; the     } the  -     return 0 ; in}

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HDU 1874

The shortest distance to walk is the output. If there is no route from S to T, then output-1.

Sample Input
3 3//Node number edge
0 1 1//u v W
0 2 3
1 2 1
0 2//Start point
3 1
0 1 1
1 2

Sample Output
2
-1

1# include <iostream>2# include <cstdio>3# include <cstring>4# include <algorithm>5# include <cmath>6# define LLLong Long7 using namespacestd;8 9 Const intmaxn= -;Ten Const intinf=0x3f3f3f3f; One intN; A BOOLVIS[MAXN]; - intCOST[MAXN][MAXN]; - intLOWCOST[MAXN]; the intPRE[MAXN]; - voidDijkstra (intBeg) - { -      for(intI=0; i<n;i++) +     { -lowcost[i]=inf;vis[i]=false;p re[i]=-1; +     } Alowcost[beg]=0; at      for(intj=0; j<n;j++) -     { -         intk=-1; -         intmin=INF; -          for(intI=0; i<n;i++) -             if(!vis[i]&&lowcost[i]<Min) in             { -min=Lowcost[i]; tok=i; +             } -             if(k==-1) the                  Break ; *vis[k]=true; $              for(intI=0; i<n;i++)Panax Notoginseng                 if(!vis[i]&&lowcost[k]+cost[k][i]<Lowcost[i]) -                 { thelowcost[i]=lowcost[k]+Cost[k][i]; +pre[i]=K; A                 } the     } +  - } $  $ intMain () - { -   //freopen ("In.txt", "R", stdin); the     intm; -      while(SCANF ("%d%d", &n, &m)! =EOF)Wuyi     { the  -         intu, V, W; Wu         intI, J; -          for(i =0; I < n; i++) About              for(j =0; J < N; J + +) $COST[I][J] =INF; -          while(m--) -         { -scanf"%d%d%d", &u, &v, &W); A             if(W < Cost[u][v])//prevent heavy edges +             { theCOST[U][V] =W; -Cost[v][u] =W; $             } the         } thescanf"%d%d", &u, &v); the Dijkstra (u); the         if(Lowcost[v]! =INF) -printf"%d\n", Lowcost[v]); in         Else theprintf"-1\n") ; the     } About  the     return 0 ; the}

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Hdu 2544 hdu 1874 Dijkstra Template questions