Segment Tree [ On the run ]

I'm trying to implement Segment Tree and maybe will solve some problems using it, prior to ICPC. Here's some resource that I'm using

• http://codeforces.com/blog/entry/3327
• http://community.topcoder.com/tc?module=Static&d1=tutorials&d2=lowestCommonAncestor
• http://apps.topcoder.com/forums/;jsessionid=2DA32E9BC12C8C331BCC8441B68E278E?module=Thread&threadID=754366&start=0&mc=4#1572259
• http://ronzii.wordpress.com/2011/07/08/segment-tree-tutorial/
• http://en.wikipedia.org/wiki/Segment_tree

[C++] Bellman Ford Implementation

Bellman-Ford is a Single Source Shortest Path (SSSP) detection algorithm. I implemented this one using a new kind of approach to coding (new for me). I used a nested class implementation. The whole BFord algorithm is packed with it's data structure in an object. The edges are also implemented using an internal class in the object. I never did nested class before this. Looks awesome.

#include <cstdio>
#include <vector>

#define INF (1<<31 - 1)
#define NIL -1

using namespace std;

class bford {
  
public:
  
  class edge {
  public:
 int u, v, w;
  };
  
  int nVertex;
  int *d, *p;
  vector<edge> elist;
  
  bford( ) {
 d = new int[0];
 p = new int[0];
 elist.clear();
  }
  
  bool function( int s, int nVertex ) {
 
 d = new int[(const int)nVertex+1];
 p = new int[(const int)nVertex+1];
 
 int i, j, w, u, v;
 // init_single_source( s ) {
 for (i=0 ; i<=nVertex ; i++) {
  d[i] = INF;
  p[i] = NIL;
 }
 d[s] = 0;
 // }
 
 for (i=0 ; i<nVertex-1 ; i++) {
  for ( j=0 ; j<elist.size() ; j++) {
   // relax( elist[j].u, elist[j].v, elist[j].w ) {
   u = elist[j].u;
   v = elist[j].v;
   w = elist[j].w;
   
   if (d[v] > d[u]+w) {
    d[v] = d[u]+w;
    p[v] = u;
   }
   // }
  }
 }
 
 for (i=0 ; i<elist.size() ; i++) {
  if ( d[ elist[i].v ] > d[ elist[i].u ] + elist[i].w ) {
   return false;
  }
 }
 return true;
  }

};

int main( void ) {
  
  int i, u, v, w, nVertex, nEdge;
  
  bford grp;
  scanf("%d",&nVertex);
  
  scanf("%d",&nEdge);
  
  for (i=0 ; i<nEdge ; i++) {
 scanf("%d %d %d",&u,&v,&w);
 grp.elist.push_back(bford::edge{u,v,w});
  }
  
  printf("%s\n",(grp.function( 1, nVertex )?"True":"False"));
  
  for (i=1 ; i<=nVertex ; i++) {
 printf("%d - %d\n",i, grp.d[i]);
  }
  
  
  return 0;
  
}