practice

Author: Pankajcoder1

README.md

@@ -4,6 +4,7 @@ Contain file of my [competitive programming](https://en.wikipedia.org/wiki/Compe
 - [Codechef](https://www.codechef.com/)
 - [Hackerrank](https://www.hackerrank.com/)
 - [Hackerearth](https://www.hackerearth.com/)
+- [Atcoder](https://atcoder.jp/home)
 - [CSES](https://cses.fi/problemset/)
 - [Facebook hacker cup](https://www.facebook.com/codingcompetitions/hacker-cup)
 

codechef/Div1/CookOff/COOK125A/SDSTRING.cpp

@@ -0,0 +1,123 @@
+/*
+    written by Pankaj Kumar.
+    country:-INDIA
+*/
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+using namespace std;
+using namespace __gnu_pbds;
+typedef long long ll ;
+typedef vector<ll> vl;
+#define speed cin.tie(0);cout.tie(0);ios_base::sync_with_stdio(0);
+// define values.
+// #define mod 1000000007
+#define phi 1.618
+/*  Abbrevations  */
+#define ff first
+#define ss second
+#define mp make_pair
+#define line cout<<endl;
+#define pb push_back
+#define Endl "\n"
+// loops
+#define forin(arr,n) for(ll i=0;i<n;i++) cin>>arr[i];
+// Some print
+#define no cout<<"NO"<<endl;
+#define yes cout<<"YES"<<endl;
+// sort
+#define all(V) (V).begin(),(V).end()
+#define srt(V) sort(all(V))
+#define srtGreat(V) sort(all(V),greater<ll>())
+#define printv(v) for(ll i=0;i<ll(v.size());i++){cout<<v[i]<<" ";} line;
+// some extra
+#define sz(V) ll(V.size())
+/* ONLINE JUDGE */
+// #ifdef ONLINE_JUDGE
+//     freopen("input.txt", "r", stdin);freopen("output.txt", "w", stdout);
+// #endif
+// template
+template <typename T>
+T mymax(T x,T y)
+{
+    return (x>y)?x:y;
+}
+// function
+
+ll power(ll x,ll y,ll mod)
+{
+    ll res=1;
+    // x=x%mod;
+    while(y>0)
+    {
+        if(y%2==1)
+        {
+            res*=x;
+            // res=res%mod;
+        }
+        y/=2; x*=x; // x=x%mod;
+    }
+    return res;
+}
+ll str_to_num(string s)
+{
+    return stoi(s);
+}
+
+string num_to_str(ll num)
+{
+    return to_string(num);
+}
+// datatype definination
+#define ordered_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
+
+/* ascii value 
+A=65,Z=90,a=97,z=122
+*/
+/*  -----------------------------------------------------------------------------------*/
+
+ll solve()
+{
+    string s;
+    cin>>s;
+    ll n=sz(s);
+    if(n&1)
+    {
+        cout<<-1<<endl;
+        return 0;
+    }
+    ll one=0,zero=0;
+    for(auto x:s)
+    {
+        if(x=='0')
+            zero++;
+        else
+            one++;
+    }
+    if(zero==n||one==n)
+    {
+        cout<<-1<<endl;
+        return 0;
+    }
+    cout<<abs(one-zero)/2<<endl;
+    return 0;
+}
+
+int main()
+{
+    speed;
+    // freopen("input.txt","r",stdin);
+    // freopen("output.txt","w",stdout);
+    ll TestCase=1;
+    cin>>TestCase;
+    while(TestCase--)
+    {
+        solve();
+    }
+}
+
+/* stuff you should look before submission 
+* int overflow
+* special test case (n=0||n=1||n=2)
+* don't get stuck on one approach if you get wrong answer
+*/