c++ - Shortest Path Implementation Issue -

i implementing shortest path problem in c++. user enters sourcevertex , function findshortestpath(int sourcevertex) finds , prints shortest paths sourcevertex remaining vertices.

void graph::findshortestpath(int sourcevertex) {     cout<<"the shortest paths "<<sourcevertex<<" are"<<endl;     //initialize shortestpatharray     for(int a=0;a<numberofvertices;a++)         shortestpatharray[a]=numeric_limits<int>::max();     shortestpatharray[sourcevertex]=0;      for(int a=0;a<numberofvertices;a++)     {         if(weightmatrix[sourcevertex][a]!=0)             shortestpatharray[a]=weightmatrix[sourcevertex][a];      }     cout<<"direct edges length"<<endl;     for(int a=0;a<numberofvertices;a++)     {         cout<<sourcevertex<<"->"<<a<<"="<<shortestpatharray[a]<<endl;     }     cout<<"shortest path after updating"<<endl;      for(int a=0;a<numberofvertices;a++)         for(int b=0;b<numberofvertices;b++)              if(weightmatrix[a][b]!=0)//edge exists             {   if(shortestpatharray[b]>(shortestpatharray[a]+weightmatrix[a][b]))             {                 shortestpatharray[b]= shortestpatharray[a]+weightmatrix[a][b];}}         for(int a=0;a<numberofvertices;a++)     cout<<sourcevertex<<"->"<<a<<"="<<shortestpatharray[a]<<endl;} 

i following output

the shortest paths 4 direct edges length 4->0=2147483647 4->1=6 4->2=10 4->3=4 4->4=0 shortest path after updating 4->0=2147483647 4->1=-2147483645 4->2=-2147483646 4->3=-2147483644 4->4=-2147483647 

the first set printed correct. in wrong in updating part. can't seem figure out.

edit-1

int main(){      graph g(5);     g.addedge(0,4,2);     g.addedge(0,2,3);     g.addedge(0,1,5);     g.addedge(1,3,6);     g.addedge(1,2,2);     g.addedge(4,3,4);     g.addedge(4,1,6);     g.addedge(4,2,10);     g.addedge(2,1,1);     g.addedge(2,3,2);     g.findshortestpath(4);      return 0;  } 

following input code

if(weightmatrix[a][b]!=0)//edge exists {        if(shortestpatharray[b]>(shortestpatharray[a]+weightmatrix[a][b]))     {         shortestpatharray[b]= shortestpatharray[a]+weightmatrix[a][b];     } } 

here e.g a=0 value of shortestpatharray[a]=2147483647; i.e max range, , in value adding more value going out of range. try smaller value max limit.