how to find short paths

[latalui]

i am a beginner, guys plizzzzzzzz help me. i am given a assignment to find short paths either using dijkstra algorithm or using binary search algorithm in linux OS.
check out what is wrong the code i tried
/program to find shortest path

#include<stdio.h>
#include<cstdlib>
#include<cstring>
#include<fstream>
#include<iostream.h>
#define member 1 // use to indicate current node
#define nonmember 0
#define infinity 999 // intial distance
struct arc
{
    int wt;
};
struct arc g[10][10];
int path[10]; 
//end of global defintn
void jointwt(struct arc g[][10], int n1, int n2 ,int wt)
// function to assign the weight on arcs
{
    g[n1][n2].wt = wt; // assign the weight to arc  n1 -n2
}
// end of function joint
 cost(struct arc c[][10], int n)
// function to get the weights
{
    int i,j,wt;
    for(i=0;i<n;i++)
    for(j=0;j<n;j++)
    {
        printf("\n weight of arc %d %d", i,j);
        scanf("%d",&wt);
        jointwt(c,i,j,wt);
    }
    printf("\n");
}
// end of function
 mat(struct arc a[][10], int n)
// function to print the weight in matrx
{
    int i,j;
    printf("\n\t");
    for(i=0;i<n;i++)
    {
         for(j=0;j<n;j++)
         {
              printf("%d",a[i][j].wt);
         }
         printf("\n\t");
    }
} //end of mat
 shortpath(int wt, int s, int t, int proced, int n)
struct arc wt[][10];
int s,t,proced[10];
int n;
{
    int dist[10], perm[10];
    int curr, i,k,dc,h=0;
    int smalldist, newdist;
    for(i=0;i<n;i++)
    {
        perm[i] = nonmember;
        dist[i] =infinity;
    }
         perm[s] = member;
                dist[s] = 0;
        curr = s;
    while(curr != t)
    {
        smalldist = infinity;
        dc = dist[curr];
         for(i=0;i<n;i++)
            if(perm[i] == nonmember)
            {
                newdist = dc + wt[curr][i].wt;
                if(newdist<smalldist)
                {
                    dist[i] = newdist;
                    proced[i] = curr;
                }
                if(dist[i]<smalldist)
                {
                    smalldist = dist[i];
                    k=i;
                }
            }
         curr = k;
        perm[curr] = member;
        path[h++] = curr;
    }
    printf("\n\t path is = %d", s+1);
     for(i=0;i<h;i++)
    printf("-> %d",path[i]+1);
    return(dist[t]);
} // end of short path
/*int cost(struct arc , int );
int mat(struct arc , int );
void jointwt(struct arc , int , int  ,int );
int shortpath(int , int , int , int , int );*/
int main()
{
    struct arc c[10][10];
    int n,s,t,proced[10];
    int x;
     printf("\n\t\t How many nodes :");
    scanf("%d",&n);
    printf("\n\t\t Enter the adjacency matrix of weight");
    printf("\n\t\t Enter 999 if no edge exits :");
    cost(c,n);
    printf("\n\t\t Weight matrix :");
    mat(c,n);
    printf("\n\t\t Enter source and distnation  :");
    scanf("%d %d",&s, &t);
    printf("\n\t\t shortest path from %d to  %d is:\n",s,t);
    x = shortpath(c, s - 1, t - 1, proced, n);
} //efmain

[r035198x]

Does the code compile and run correctly then? Better tell us a specific problem rather than ask us to look for errors in your code.

[gpraghuram]

Usually shortest distance will be computed with help of Graphs.
You should start from there.

raghu

[Banfa]

Perhaps you could list the specific compiler errors you do not understand.

[latalui]

Does the code compile and run correctly then? Better tell us a specific problem rather than ask us to look for errors in your code.

errors in codes are
ISO C++ forbids declaration of `cost' with no type
shortestpath.c: 38: error: ISO C++ forbids declaration of `mat' with no type
shortestpath.c: 51: error: expected constructor, destructor, or type conversion before "struct"
shortestpath.c: 51: error: expected `,' or `;' before "struct"
shortestpath.c: 54: error: expected unqualified-id before '{' token
shortestpath.c: 54: error: expected `,' or `;' before '{' token
shortestpath.c: In function `int main()':
shortestpath.c: 113: error: `shortpath' undeclared (first use this function)
shortestpath.c: 113: error: (Each undeclared identifier is reported only once for each function it appears in.)

[latalui]

Perhaps you could list the specific compiler errors you do not understand.

errors are:-
forbids declaration of `cost' with no type
shortestpath.c: 38: error: ISO C++ forbids declaration of `mat' with no type
shortestpath.c: 51: error: expected constructor, destructor, or type conversion before "struct"
shortestpath.c: 51: error: expected `,' or `;' before "struct"
shortestpath.c: 54: error: expected unqualified-id before '{' token
shortestpath.c: 54: error: expected `,' or `;' before '{' token
shortestpath.c: In function `int main()':
shortestpath.c: 113: error: `shortpath' undeclared (first use this function)
shortestpath.c: 113: error: (Each undeclared identifier is reported only once for each function it appears in.)

[arnaudk]

Usually shortest distance will be computed with help of Graphs.
You should start from there.

raghu

That depends what is meant by "shortest distance". If the OP means "the least distance connecting N points with straight lines" then you use graph theory (i.e. calculate the minimum spanning tree or work out the Steiner tree problem if you can add intermediate points). If it's just the shortest distance between two points along some cost function then you don't need graph theory, the problem can be solved numerically using Dijkstra's algorithm.

[Banfa]

errors are:-
forbids declaration of `cost' with no type
shortestpath.c: 38: error: ISO C++ forbids declaration of `mat' with no type
shortestpath.c: 51: error: expected constructor, destructor, or type conversion before "struct"
shortestpath.c: 51: error: expected `,' or `;' before "struct"
shortestpath.c: 54: error: expected unqualified-id before '{' token
shortestpath.c: 54: error: expected `,' or `;' before '{' token
shortestpath.c: In function `int main()':
shortestpath.c: 113: error: `shortpath' undeclared (first use this function)
shortestpath.c: 113: error: (Each undeclared identifier is reported only once for each function it appears in.)

Now take each error in turn and examine the line of code given and the line of code before that error. For instance

shortestpath.c: 38: error: ISO C++ forbids declaration of `mat' with no type

Line 38 is the definition of you function mat, do you see anything wrong with how you have defined mat?