need help with sorting algorithm :(
Author
Hi guys
I have a class like this
class Node{
.....
int h;
...
};
then a vector contain pointer to Node:
vector<Node*> nodeList;
Now im trying to compare h from each pointer from nodeList then sort all the pointers in the ascending order (due to h)
I tried to do this
If(nodeList->GetH() > nodeList[i+1]->GetH())
{
//swap element i to i+1
}
but eventually it will give me an out of bound error :(. So what should I do
Thx in advance
}
Question: Is all you care about is getting this sorted, or are you trying to learn the basics of sorting?
If the former, write a function that compares your structures, and use std::sort.
If the latter, you appear to be performing bubble sort, this is rarely a good choice. There are a few articles on Gamedev that discuss alternatives. But your specific problem is probably an off by one error. Your array only has N elements, and you are likely looping something like for(int i = 0; i < N; i++). This causes your last iteration to compare nodeList[i-1] to nodeList, but nodeList is not a valid element. Dwell on that a bit, and a solution should come to you.
CM
If the former, write a function that compares your structures, and use std::sort.
If the latter, you appear to be performing bubble sort, this is rarely a good choice. There are a few articles on Gamedev that discuss alternatives. But your specific problem is probably an off by one error. Your array only has N elements, and you are likely looping something like for(int i = 0; i < N; i++). This causes your last iteration to compare nodeList[i-1] to nodeList, but nodeList is not a valid element. Dwell on that a bit, and a solution should come to you.
CM
#include <algorithm>#include <vector>using namespace std;struct node{ node( int n ) : h(n) {}; int h;}bool compare_node_ptr( const node* const left, const node* const right ){ return (left->h < right->h);}int main(){ vector<node*> nodelist; node n1( 5 ), n2( 1 ), n3( 3 ); nodelist.push_back( &n1 ); nodelist.push_back( &n2 ); nodelist.push_back( &n3 ); sort( nodelist.begin(), nodelist.end(), compare_node_ptr ); return 0;}edit: Awww. Beaten to it.
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