hdu2544

dijkstra

   
     

    
      #include
    
      "
    
      iostream
    
      "
    
      

    
      #define
    
       Max 999999
    
      

    
      using
    
       
    
      namespace
    
       std;

    
      int
    
       map[
    
      1001
    
      ][
    
      1001
    
      ];

    
      int
    
       visit[
    
      1001
    
      ];

    
      int
    
       n,m;

    
      int
    
       a,b,time;

    
      int
    
       i,j,k,_min;

    
      int
    
       len;

    
      void
    
       DJ()
{
 
    
      for
    
      (i
    
      =
    
      1
    
      ;i
    
      <=
    
      len;i
    
      ++
    
      )
 {
 _min
    
      =
    
      Max;

 
    
      for
    
      (j
    
      =
    
      1
    
      ;j
    
      <=
    
      len;j
    
      ++
    
      )
 {
 
    
      if
    
      (
    
      !
    
      visit[j] 
    
      &&
    
       map[
    
      0
    
      ][j]
    
      <
    
      _min)
 {
 _min
    
      =
    
      map[
    
      0
    
      ][j];
 k
    
      =
    
      j;
 }
 }
 
    
      if
    
      (_min
    
      ==
    
      Max) 
    
      break
    
      ;

 visit[k]
    
      =
    
      1
    
      ;
 
    
      for
    
      (
    
      int
    
       p
    
      =
    
      1
    
      ;p
    
      <=
    
      len;p
    
      ++
    
      )
 {
 
    
      if
    
      (
    
      !
    
      visit[p] 
    
      &&
    
       map[
    
      0
    
      ][p]
    
      >
    
      map[
    
      0
    
      ][k]
    
      +
    
      map[k][p])
 {
 map[
    
      0
    
      ][p]
    
      =
    
      map[
    
      0
    
      ][k]
    
      +
    
      map[k][p];
 
 }
 }
 }
}

    
      int
    
       main()
{
 
 
    
      while
    
      (cin
    
      >>
    
      n
    
      >>
    
      m,n
    
      +
    
      m)
 {
 
    
      for
    
      (i
    
      =
    
      0
    
      ;i
    
      <
    
      1001
    
      ;i
    
      ++
    
      )
 {
 
    
      for
    
      (j
    
      =
    
      0
    
      ;j
    
      <
    
      1001
    
      ;j
    
      ++
    
      )
 map[i][j]
    
      =
    
      Max;
 }
 len
    
      =
    
      0
    
      ;
 
    
      for
    
      (i
    
      =
    
      0
    
      ;i
    
      <
    
      m;i
    
      ++
    
      )
 {
 scanf(
    
      "
    
      %d%d%d
    
      "
    
      ,
    
      &
    
      a,
    
      &
    
      b,
    
      &
    
      time);

 
    
      if
    
      (map[a][b]
    
      >
    
      time) map[a][b]
    
      =
    
      map[b][a]
    
      =
    
      time;
 
    
      if
    
      (len
    
      <
    
      a) len
    
      =
    
      a;
 
    
      if
    
      (len
    
      <
    
      b) len
    
      =
    
      b;
 }
 memset(visit,
    
      0
    
      ,
    
      sizeof
    
      (visit));

 map[
    
      0
    
      ][
    
      1
    
      ]
    
      =
    
      0
    
      ;
 DJ();
 cout
    
      <<
    
      map[
    
      0
    
      ][n]
    
      <<
    
      endl; 
 }
 
    
      return
    
       
    
      0
    
      ;
}
   
     

floyd

   
     

    
      #include
    
      "
    
      iostream
    
      "
    
      

    
      #define
    
       Max 999999 
    
      

    
      using
    
       
    
      namespace
    
       std;

    
      int
    
       map[
    
      1001
    
      ][
    
      1001
    
      ];

    
      int
    
       visit[
    
      1001
    
      ];

    
      int
    
       n,m;

    
      int
    
       a,b,time;

    
      int
    
       i,j,k,_min;

    
      int
    
       len;

    
      void
    
       Floyd()
{
 
    
      for
    
      (k
    
      =
    
      1
    
      ;k
    
      <=
    
      len;k
    
      ++
    
      )
 {
 
    
      for
    
      (i
    
      =
    
      1
    
      ;i
    
      <=
    
      len;i
    
      ++
    
      )
 {
 
    
      for
    
      (j
    
      =
    
      1
    
      ;j
    
      <=
    
      len;j
    
      ++
    
      )
 {
 
    
      if
    
      (
    
      !
    
      visit[j] 
    
      &&
    
       map[i][j]
    
      >
    
      map[i][k]
    
      +
    
      map[k][j])
 map[i][j]
    
      =
    
      map[i][k]
    
      +
    
      map[k][j];
 }
 }
 }
}

    
      int
    
       main()
{
 
 
    
      while
    
      (cin
    
      >>
    
      n
    
      >>
    
      m,n
    
      +
    
      m)
 {
 
    
      for
    
      (i
    
      =
    
      0
    
      ;i
    
      <
    
      1001
    
      ;i
    
      ++
    
      )
 {
 
    
      for
    
      (j
    
      =
    
      0
    
      ;j
    
      <
    
      1001
    
      ;j
    
      ++
    
      )
 map[i][j]
    
      =
    
      Max;
 }
 len
    
      =
    
      0
    
      ;
 
    
      for
    
      (i
    
      =
    
      0
    
      ;i
    
      <
    
      m;i
    
      ++
    
      )
 {
 scanf(
    
      "
    
      %d%d%d
    
      "
    
      ,
    
      &
    
      a,
    
      &
    
      b,
    
      &
    
      time);

 
    
      if
    
      (map[a][b]
    
      >
    
      time) map[a][b]
    
      =
    
      map[b][a]
    
      =
    
      time;
 
    
      if
    
      (len
    
      <
    
      a) len
    
      =
    
      a;
 
    
      if
    
      (len
    
      <
    
      b) len
    
      =
    
      b;
 }
 memset(visit,
    
      0
    
      ,
    
      sizeof
    
      (visit));
 map[
    
      0
    
      ][
    
      1
    
      ]
    
      =
    
      0
    
      ;
 Floyd();
 cout
    
      <<
    
      map[
    
      1
    
      ][n]
    
      <<
    
      endl;
 }
 
    
      return
    
       
    
      0
    
      ;
}
   
     

View Code

   
     

    
      #include
    
      <
    
      stdio.h
    
      >
    
      
#include
    
      <
    
      string
    
      .h
    
      >
    
      

    
      #define
    
       Max 999999999 
    
      

    
      #define
    
       M 1005
    
      

    
      #define
    
       N 1001
    
      

    
      int
    
       map[M][M];

    
      int
    
       dir[M];

    
      int
    
       n , m ;

    
      int
    
       a , b , c ;

    
      int
    
       len;


    
      void
    
       DJ( 
    
      int
    
       v)
{
 
    
      bool
    
       visit[N]
    
      =
    
      {
    
      false
    
      };
 
 
    
      int
    
       i , j , p;
 
    
      for
    
      (i 
    
      =
    
       
    
      1
    
       ; i 
    
      <=
    
       n ; i
    
      ++
    
       )
 dir[i]
    
      =
    
      map[v][i];
 dir[v]
    
      =
    
      0
    
      ;
 visit[v]
    
      =
    
      true
    
      ;
 
    
      for
    
      (i
    
      =
    
      1
    
      ;i
    
      <=
    
      n;i
    
      ++
    
      )
 {
 
    
      int
    
       Min 
    
      =
    
       Max;
 
    
      int
    
       k 
    
      =
    
       v ;
 
    
      for
    
      (j
    
      =
    
      1
    
      ;j
    
      <=
    
      n;j
    
      ++
    
      )
 {
 
    
      if
    
      (
    
      !
    
      visit[j] 
    
      &&
    
       dir[j] 
    
      <
    
       Min )
 {
 
 k 
    
      =
    
       j;
 Min 
    
      =
    
       dir[j];
 }
 }
 visit[k] 
    
      =
    
       
    
      true
    
       ;
 
    
      for
    
      ( p
    
      =
    
      1
    
       ; p
    
      <=
    
      n; p
    
      ++
    
      )
 {
 
    
      if
    
      (
    
      !
    
      visit[p] 
    
      &&
    
       map[k][p] 
    
      <
    
       Max 
    
      &&
    
       dir[p] 
    
      >
    
       dir[k] 
    
      +
    
       map[k][p] )
 {
 dir[p] 
    
      =
    
       dir[k] 
    
      +
    
       map[k][p];
 }
 }
 }
}

    
      int
    
       main()
{
 
 
    
      while
    
      (scanf(
    
      "
    
      %d%d
    
      "
    
      ,
    
      &
    
      n,
    
      &
    
      m)
    
      !=
    
      EOF
    
      &&
    
      (n
    
      +
    
      m))
 {
 
    
      int
    
       i,j;
 
    
      for
    
      (i 
    
      =
    
       
    
      0
    
       ; i 
    
      <=
    
       
    
      1000
    
       ; i
    
      ++
    
      )
 
    
      for
    
      (j
    
      =
    
      0
    
       ; j 
    
      <=
    
       i; j
    
      ++
    
      )
 {
 map[i][j] 
    
      =
    
       Max;
 map[j][i] 
    
      =
    
       Max;
 } 
 
 
    
      for
    
      (i
    
      =
    
      0
    
      ;i
    
      <
    
      m;i
    
      ++
    
      )
 {
 scanf(
    
      "
    
      %d%d%d
    
      "
    
      ,
    
      &
    
      a,
    
      &
    
      b,
    
      &
    
      c);
 
    
      if
    
      (map[a][b]
    
      >
    
      c) map[a][b] 
    
      =
    
       map[b][a] 
    
      =
    
       c;
 
 }
 
 DJ(
    
      1
    
      );
 printf(
    
      "
    
      %d\n
    
      "
    
      ,dir[n]);
 
 }
 
    
      return
    
       
    
      0
    
      ;
 
}