Untitled

#include <iostream>
#include <set>
#include <algorithm>
using namespace std;
struct res {
    int mCost, mContent;
};
struct Mineral {
    int cost, mineID, content;
};
struct comp {                  
    bool operator()(Mineral m1, Mineral m2) const {
        return m1.cost < m2.cost;
    }
};
set<Mineral, comp> mine_comb[2][3];   
int shipfee;
  
void init(int mShipFee) {
    for (int i = 0; i < 3; i++) {
        for (int j = 0; j < 3; j++)
            mine_comb[i][j].clear();
    }
    shipfee = mShipFee;
}
int gather(int mMineId, int mType, int mCost, int mContent) {
    Mineral mid;
    mid.content = mContent; mid.cost = mCost; mid.mineID = mMineId;
    mine_comb[mMineId][mType].insert(mid);
    mine_comb[2][mType].insert(mid);   
    return mine_comb[mMineId][mType].size();
}
res mix(int mBudget) {
    int row = -1;
    res res;
    res.mContent = 0; res.mCost = 0;
    int price = 0;                  
    int content = -1;               
    Mineral del[3];                 
  
    for (int i = 0; i < 3; i++) {    
        auto m = mine_comb[i][0].begin();  
        auto m1 = mine_comb[i][1].begin(); 
        auto m2 = mine_comb[i][2].begin(); 
        while (m != mine_comb[i][0].end() && m1 != mine_comb[i][1].end() && m2 != mine_comb[i][2].end())
        {
            int p = m->cost + m1->cost + m2->cost + shipfee;  
            if (i == 2)p += shipfee;                          
  
            if (p <= mBudget) {                                       
                int c = min({ m->content,m1->content,m2->content });  
  
                if (c > content || (c == content && p < price)) {     
                    content = c;
                    price = p;
                    del[0] = *(m);                                 
                    del[1] = *(m1);
                    del[2] = *(m2);
                    row = i;
                }
                if (m->content == c)m++;                                           
                else if (m1->content == c)m1++;
                else m2++;
            }
            else break;                                             
        }
    }
    if (price != 0) {                                                 
        mine_comb[row][0].erase(del[0]); 
        mine_comb[row][1].erase(del[1]); 
        mine_comb[row][2].erase(del[2]);
  
        mine_comb[2][0].erase(del[0]);
        mine_comb[2][1].erase(del[1]); 
        mine_comb[2][2].erase(del[2]);
  
        res.mCost = price;                                        
        res.mContent = content;
    }
    return res;                                                     
}