Merge pull request #215 from ViMo018/patch-2

Solved First Question of Day2

Author: Dheeraj-06

Problems/Mathematics/Day-02/sol/Vishva/Soln1.cpp

@@ -0,0 +1,66 @@
+#include<bits/stdc++.h>
+#include<queue>
+using namespace std;
+typedef unordered_map<int, int> umii;
+typedef unordered_map<long long, long long> umll;
+typedef unordered_map<char, long long> umci;
+typedef vector<pair<int, int>> vpi;
+typedef vector<int> vi;
+typedef long long ll;
+typedef vector<long long> vll;
+typedef unordered_map<int , bool> umib;
+#define sum(v) accumulate(v.begin(), v.end(), 0)
+#define endl '\n'
+#define f0(i, n) for(long long i = 0; i < n; i++)
+#define f1(i, n) for(long long i = 1; i < n; i++)
+#define as(v) sort(v.begin(), v.end())
+#define all(x) (x).begin(), (x).end()
+#define pb push_back
+template<class T> umll frequency(vector<T> &v) {umll freq;for(auto &x:v) freq[x]++; return freq;}
+template<class T> umci S_frequency(vector<T> &v) {umci freq;for(auto &x:v) freq[x]++; return freq;}
+template <class T> void input(vector<T> &v){for(auto &x:v)cin>>x;}
+ll power(ll x, ll y){ ll res = 1; while (y > 0){ if (y & 1) res = (ll)(res*x); y = y>>1; x = (ll)(x*x); } return res; }
+void pvll(const vector<long long> &arr){for(auto it : arr){cout << it << " ";}cout << endl;}
+void pvi(const vector<int> &arr){for(auto it : arr){cout << it << " ";}cout << endl;}
+
+
+void solve(){
+
+//-------------INPUT-------------
+    ll n; 
+    cin >> n;
+    vll v(n);
+    input(v);
+    sort(all(v));
+    map<ll,ll>mp;
+    ll req = abs(v[n-1]-v[0]);
+    ll ans=0;
+    for(ll i=0;i<n;i++)
+    {
+        ll target = (v[i]-req);
+        if(mp.find(target)!=mp.end())
+        {
+            // cout << v[i] << " " <<  target << " ";
+            ans+= (mp[target]);
+        }
+        mp[v[i]]++;
+    }  
+    cout << 2*ans << endl; 
+
+    // explanation :- this is basic 2 sum type question where map stores the frequency of previous elements 
+    // time complexity is o(nlogn)
+    
+    // submission link:- https://codeforces.com/contest/1771/submission/355275950
+
+
+//-------------CODE--------------
+    
+
+
+}
+
+
+int main(){
+    int tt; cin >> tt; while(tt--)
+{solve();};
+}