I want to sort in ascending order according to the first element of the inner pair, i.e. a
in this case. But its not at all sorting. I am not sure if my function func
logic is correct.
#include<iostream>
#include<algorithm>
#include<vector>
using namespace std;
bool func(const pair<int,pair<int,int> >&i , const pair<int,pair<int,int> >&j )
{
i.second.first < j.second.first ;
}
int main()
{
vector<pair<int,pair<int,int> > > v;
pair<int,int> pi;
pair<int,pair<int,int> > po;
int n,a,b,c,i;
cin>>n;
while(n--)
{
cin>>a>>b>>c;
pi=make_pair(a,b);
po=make_pair(c,pi);
v.push_back(po);
}
cout<<endl;
for(i=0;i<v.size();i++)
{
cout<<v[i].second.first<<" "<<v[i].second.second<<" "<<v[i].first<<endl;
}
sort(v.begin(),v.end(),func);
cout<<endl;
for(i=0;i<v.size();i++)
{
cout<<v[i].second.first<<" "<<v[i].second.second<<" "<<v[i].first<<endl;
}
return 0;
}