Fractional Knapsack

// problem url: https://www.codingninjas.com/codestudio/problems/975286?topList=striver-sde-sheet-problems&utm_source=striver&utm_medium=website&leftPanelTab=0
// mode: Easy
// Greedy and Sorting

#include <bits/stdc++.h>
bool compare(pair<int,int> p1, pair<int,int> p2){
    double p1Ratio = ((double)p1.second/p1.first);
    double p2Ratio = ((double)p2.second/p2.first);
    
    if(p1Ratio > p2Ratio)    return true;
    return false;
}
double maximumValue (vector<pair<int, int>>& items, int n, int w){
    stable_sort(items.begin(), items.end(), compare);
    double totalVal = 0;
    for(int i=0; i<n; i++){
        if(w < items[i].first){
            totalVal += (w * ((double)items[i].second/items[i].first));
            break;
        }
        totalVal += items[i].second;
        w -= items[i].first;
    }
    return totalVal;
}