added code with right naming convension

Author: ishan-nahid

ONLINE JUDGE/CodeChef Challenges/Alternate_Additions.cpp

@@ -0,0 +1,53 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+#define ll long long
+#define pb(x) push_back(x)
+
+void setup();
+void solve();
+
+int main()
+{
+	setup();
+	solve();
+	return 0;
+}
+
+void solve()
+{
+	ll t;
+	cin >> t;
+	while(t--)
+	{
+		ll a, b;
+		cin >> a >> b;
+
+		if(b-a == 1 || b-a == 3) cout << "YES" << endl;
+		else if(b-a == 2) cout << "NO" << endl;
+		else
+		{
+			if((b-a)%3 == 0 || (b-a)%3 == 1) cout << "YES" << endl;
+			else cout << "NO" << endl;
+			// if(a%2 == 0 && b%2 == 0)
+			// else if(a%2 != 0 && b%2 != 0)
+			// else if(a%2 == 0 && b%2 != 0)
+			// else if(a%2 != 0 && b%2 == 0)
+		}
+	}
+}
+void setup()
+{
+	ios::sync_with_stdio(false);
+    cin.tie(NULL);
+    cout.tie(NULL);
+	#ifndef ONLINE_JUDGE
+    freopen("input.txt", "r", stdin);
+    freopen("output.txt", "w", stdout);
+	#else
+	#endif
+}
+
+// 2 -> 3, 5, 6, 8, 9, 11, 12
+// 3 -> 4, (6, 7,) (9, 10,) (12, 13)
+// 4 -> 5, 7, 8, 10, 11, 13, 14

ONLINE JUDGE/CodeChef Challenges/Chairs_Requirement.cpp

@@ -0,0 +1,39 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+#define ll long long
+#define pb(x) push_back(x)
+
+void setup();
+void solve();
+
+int main()
+{
+	setup();
+	solve();
+	return 0;
+}
+
+void solve()
+{
+	ll t, x, y;
+	cin >> t;
+
+	while(t--)
+	{
+		cin >> x >> y;
+		if(x > y) cout << (x-y) << endl;
+		else cout << 0 << endl;
+	} 
+}
+void setup()
+{
+	ios::sync_with_stdio(false);
+    cin.tie(NULL);
+    cout.tie(NULL);
+	#ifndef ONLINE_JUDGE
+    freopen("input.txt", "r", stdin);
+    freopen("output.txt", "w", stdout);
+	#else
+	#endif
+}

ONLINE JUDGE/CodeChef Challenges/Equal_Strings.cpp

@@ -0,0 +1,64 @@
+#include <bits/stdc++.h>
+#include <math.h>
+using namespace std;
+
+#define ll long long
+#define pb(x) push_back(x)
+
+void setup();
+void solve();
+
+int main()
+{
+	setup();
+	solve();
+	return 0;
+}
+
+void solve()
+{
+	ll t;
+	cin >> t;
+	while(t--)
+	{
+		ll n;
+		string s1, s2;
+
+		cin >> n >> s1 >> s2;
+
+		ll ss1 = s1.size(), ss2 = s2.size();
+
+		set <char> s;
+		ll c = 0;
+		for(ll i = 0; i < ss1; i++)
+		{
+			if(s1[i] != s2[i])
+			{
+				c++;
+				s.insert(s2[i]);
+			}
+		}
+
+		// cout << c << " " << s.size() << endl;
+		// for (auto itr : s)
+		//   {
+		//     cout << itr << " ";
+		//   }
+		//   cout << endl;
+		if(c > s.size()) cout << s.size() << endl;
+		else cout << c << endl;
+
+	}
+}
+void setup()
+{
+	ios::sync_with_stdio(false);
+    cin.tie(NULL);
+    cout.tie(NULL);
+	#ifndef ONLINE_JUDGE
+    freopen("input.txt", "r", stdin);
+    freopen("output.txt", "w", stdout);
+	#else
+	#endif
+}
+

ONLINE JUDGE/CodeChef Challenges/MINSM.cpp

@@ -0,0 +1,62 @@
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#define ll        long long
+#define frp(a, b) for(ll i = a; i < b; i++)
+#define frn(a, b) for(ll i = a; i > b; i--)
+
+#define in(x)     insert(x)
+#define pb(x)     push_back(x)
+#define full(x)   x.begin(),x.end()
+
+ll gcd(ll a, ll b);
+void setup();
+void solve();
+
+int main()
+{
+	setup();
+	solve();
+	return 0;
+}
+
+void solve()
+{
+	ll T, N;
+	cin >> T;
+	while(T--)
+	{
+	    cin >> N;
+	    
+	     vector <ll> v(N);
+	     
+	     frp(0, N) cin >> v[i];
+	     
+	     sort(v.begin(), v.end());
+
+	     ll g = v[0];
+
+	     for(ll j = 1; j < N; j++) g = gcd(g, v[j]);
+
+	     cout << g*N << endl;
+
+	}
+}
+
+ll gcd(ll a, ll b)
+{
+	if(a%b == 0) return b;
+	else return gcd(b, a%b);
+}
+void setup()
+{
+	ios::sync_with_stdio(false);
+    cin.tie(NULL);
+    cout.tie(NULL);
+	#ifndef ONLINE_JUDGE
+    freopen("input.txt", "r", stdin);
+    freopen("one.txt", "w", stdout);
+	#else
+	#endif
+}

ONLINE JUDGE/CodeChef Challenges/SEGM01.cpp

@@ -0,0 +1,69 @@
+#include <iostream>
+#include <cmath>
+#include <algorithm>
+
+using namespace std;
+
+void solve();
+
+int main()
+{
+
+    solve();
+
+    return 0;
+}
+
+void solve()
+{
+	int t;
+	string s;
+
+	cin >> t;
+
+	while(t--)
+	{
+		cin >> s;
+
+		int ss = s.size(), f = 0, c = 0;
+
+		for(int i = 0; i < ss; i++)
+		{
+			if(s[i] == 49)
+			{
+				c++;
+				f = i;
+			}
+		}
+
+		if(c == 0)
+		{
+			cout << "NO" << endl;
+		}
+		else
+		{
+			for(int i = f; i >= 0; i--)
+			{
+				if(s[i] == 48)
+				{
+					break;
+				}
+				else
+				{
+					c--;
+				}
+			}
+
+			//cout << c << endl;
+			if(c == 0)
+			{
+				cout << "YES" << endl;
+			}
+			else
+			{
+				cout << "NO" << endl;
+			}
+		}
+		
+	}
+}

ONLINE JUDGE/CodeChef Challenges/Subscriptions.cpp

@@ -0,0 +1,40 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+#define ll long long
+#define pb(x) push_back(x)
+
+void setup();
+void solve();
+
+int main()
+{
+	setup();
+	solve();
+	return 0;
+}
+
+void solve()
+{
+	ll t;
+	cin >> t;
+	while(t--)
+	{
+		ll n, x;
+		cin >> n >> x;
+
+		if(n <= 6) cout << x << endl;
+		else cout << int(ceil(n/6.0)*x) << endl;
+	}
+}
+void setup()
+{
+	ios::sync_with_stdio(false);
+    cin.tie(NULL);
+    cout.tie(NULL);
+	#ifndef ONLINE_JUDGE
+    freopen("input.txt", "r", stdin);
+    freopen("output.txt", "w", stdout);
+	#else
+	#endif
+}