Hacktober_Part-2

Arrays/Fast exponentiation.cpp

@@ -0,0 +1,70 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+#define ff              first
+#define ss              second
+#define int             long long
+#define ull             unsigned long long int
+#define ll              long long int
+#define pb              push_back
+#define mp              make_pair
+#define pii             pair<int,int>
+#define vi              vector<int>
+#define vii             vector<int,int>
+#define vpii            vector<pair<int,int>>
+#define mii             map<int,int>
+#define pqb             priority_queue<int>
+#define pqs             priority_queue<int,vi,greater<int> >
+#define setbits(x)      __builtin_popcountll(x)
+#define zrobits(x)      __builtin_ctzll(x)
+#define mod             1000000007
+#define inf             1e18
+#define yes             cout<<"YES"<<endl;
+#define no              cout<<"NO"<<endl;
+#define ps(x,y)         fixed<<setprecision(y)<<x
+#define mk(arr,n,type)  type *arr=new type[n];
+#define w(x)            int x; cin>>x; while(x--)
+#define FIO             ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
+#define dec(n,v)        int n; cin>>n; vector<int> v(n);for(int i=0;i<n;i++)cin>>v[i];
+#define decl(n,v)       int n; cin>>n; vector<int> v(n+1);for(int i=1;i<=n;i++)cin>>v[i];
+mt19937                 rng(chrono::steady_clock::now().time_since_epoch().count());
+
+void c_a_j()
+{
+#ifndef ONLINE_JUDGE
+	freopen("input.txt", "r", stdin);
+	freopen("output.txt", "w", stdout);
+#endif
+}
+int FastExp(int a, int n)
+{
+	if (n == 0)return 1;
+	int x = FastExp(a, n / 2);         //subproblem
+
+	if (n & 1)                         // if n is odd
+	{
+		return a * x * x;             //a^n = a*(a^n/2)^2;
+	}
+	return x * x;                    //a^n = (a^n/2)^2;
+}
+void solve()
+{
+	int a, n;
+	cin >> a >> n;
+	cout << FastExp(a, n) << "\n";
+}
+int32_t main()
+{
+#ifdef SIEVE
+	sieve();
+#endif
+#ifdef NCR
+	init();
+#endif
+
+	FIO
+	c_a_j();
+
+	solve();
+	return 0;
+}

Arrays/memory_scene.cpp

@@ -0,0 +1,113 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+#define ff              first
+#define ss              second
+#define int             long long
+#define pb              push_back
+#define pii             pair<int,int>
+#define vi              vector<int>
+#define setbits(x)      __builtin_popcountll(x)
+#define mod             1000000007
+#define inf             1e18
+#define all(v)          v.begin(),v.end()
+#define ps(x,y)         fixed<<setprecision(y)<<x
+#define w(x)            int x; cin>>x; while(x--)
+#define FIO             ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
+
+// for debug
+#ifndef ONLINE_JUDGE
+#define debug(x) cerr << #x <<" "; _print(x); cerr << endl;
+#else
+#define debug(x)
+#endif
+
+void _print(int t) {cerr << t;}
+void _print(string t) {cerr << t;}
+void _print(char t) {cerr << t;}
+void _print(double t) {cerr << t;}
+
+template <class T, class V> void _print(pair <T, V> p);
+template <class T> void _print(vector <T> v);
+template <class T> void _print(set <T> v);
+template <class T, class V> void _print(map <T, V> v);
+template <class T> void _print(multiset <T> v);
+template <class T, class V> void _print(pair <T, V> p) {cerr << "{"; _print(p.ff); cerr << ","; _print(p.ss); cerr << "}";}
+template <class T> void _print(vector <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(set <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(multiset <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T, class V> void _print(map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
+
+//some maths
+int M;
+inline int gcd(int a, int b) { return b == 0 ? a : gcd(b, a % b); }
+inline int lcm(int a, int b) { return (a * b) / gcd(a, b); }
+inline int Mod(int x) { return (x % M + M) % M; }
+inline int add_Mod(int a, int b) {return Mod(Mod(a) + Mod(b));}
+inline int sub_Mod(int a, int b) {return Mod(Mod(a) - Mod(b) + M);}
+inline int mul_Mod(int a, int b) {return Mod(Mod(a) * Mod(b));}
+inline int FastModExp(int a, int b) {M = mod; int res = 1; while (b > 0) {if (b & 1)res = mul_Mod(res, a); a = mul_Mod(a, a); b = b >> 1;} return res;}
+inline int mmi(int y) { return FastModExp(y, M - 2);}
+inline int div_Mod(int a, int b) { return mul_Mod(a, mmi(b));}
+inline void extendedEuclidMethod(int a, int b, int &x, int &y) { if (b == 0) {x = 1; y = 0; return;} extendedEuclidMethod(b, a % b, x, y); int cX = y; int cY = x - (a / b) * y; x = cX; y = cY;}
+
+void c_a_j()
+{
+#ifndef ONLINE_JUDGE
+    freopen("input.txt", "r", stdin);
+    freopen("output.txt", "w", stdout);
+    freopen("error.txt", "w", stderr);
+#endif
+}
+bool check_prime(int n)
+{
+    for (int i = 2; i <= sqrt(n); i++)
+    {
+        if (n % i == 0)return false;
+    }
+    return true;
+}
+void solve()
+{
+    int k; cin >> k;
+    string s; cin >> s;
+    for (int i = 0; i < k; i++)
+    {
+        if (s[i] == '1' || s[i] == '4' || s[i] == '6' || s[i] == '8' || s[i] == '9')
+        {
+            cout << 1 << endl;
+            cout << s[i] - '0' << endl;
+            return;
+        }
+    }
+
+    //now number only consists of digits 2,3,5,7 so checking all combinations
+    for (int i = 0; i < k; i++)
+    {
+        for (int j = i + 1; j < k; j++)
+        {
+            int x = s[i] - '0', y = s[j] - '0';
+            if (!check_prime(x * 10 + y))
+            {
+                cout << 2 << endl;
+                cout << x  << y << endl;
+                return;
+            }
+        }
+    }
+}
+int32_t main()
+{
+#ifdef SIEVE
+    sieve();
+#endif
+#ifdef NCR
+    init();
+#endif
+
+    FIO
+    c_a_j();
+
+    w(x)solve();
+    return 0;
+}

BasicsofC/matrixmultiplication.cpp

@@ -0,0 +1,47 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+void solve()
+{
+    int n; cin >> n;
+    int arr1[n][n], arr2[n][n], res[n][n];
+    memset(res, 0, sizeof res);
+
+    //input part
+    for (int i = 0; i < n; i++)
+    {
+        for (int j = 0; j < n; j++)cin >> arr1[i][j];
+    }
+    for (int i = 0; i < n; i++)
+    {
+        for (int j = 0; j < n; j++)cin >> arr2[i][j];
+    }
+
+    //initialisation
+    int i = 0, j = 0, k = 0;
+
+    //solving part
+    for (int i = 0; i < n; i++)
+    {
+        for (int j = 0; j < n; j++)
+        {
+            for (int k = 0; k < n; k++)
+            {
+                res[i][j] += arr1[i][k] * arr2[k][j];
+            }
+        }
+    }
+
+    //printing
+    for (int i = 0; i < n; i++)
+    {
+        for (int j = 0; j < n; j++)cout << res[i][j] << " ";
+
+        cout << endl;
+    }
+}
+int main()
+{
+    solve();
+    return 0;
+}

ExtraDSAQ/atm_students.cpp

@@ -0,0 +1,106 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+#define ff              first
+#define ss              second
+#define int             long long
+#define pb              push_back
+#define pii             pair<int,int>
+#define vi              vector<int>
+#define setbits(x)      __builtin_popcountll(x)
+#define mod             1000000007
+#define inf             1e18
+#define all(v)          v.begin(),v.end()
+#define ps(x,y)         fixed<<setprecision(y)<<x
+#define w(x)            int x; cin>>x; while(x--)
+#define FIO             ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
+
+// for debug
+#ifndef ONLINE_JUDGE
+#define debug(x) cerr << #x <<" "; _print(x); cerr << endl;
+#else
+#define debug(x)
+#endif
+
+void _print(int t) {cerr << t;}
+void _print(string t) {cerr << t;}
+void _print(char t) {cerr << t;}
+void _print(double t) {cerr << t;}
+
+template <class T, class V> void _print(pair <T, V> p);
+template <class T> void _print(vector <T> v);
+template <class T> void _print(set <T> v);
+template <class T, class V> void _print(map <T, V> v);
+template <class T> void _print(multiset <T> v);
+template <class T, class V> void _print(pair <T, V> p) {cerr << "{"; _print(p.ff); cerr << ","; _print(p.ss); cerr << "}";}
+template <class T> void _print(vector <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(set <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(multiset <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T, class V> void _print(map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
+
+//some maths
+int M;
+inline int gcd(int a, int b) { return b == 0 ? a : gcd(b, a % b); }
+inline int lcm(int a, int b) { return (a * b) / gcd(a, b); }
+inline int Mod(int x) { return (x % M + M) % M; }
+inline int add_Mod(int a, int b) {return Mod(Mod(a) + Mod(b));}
+inline int sub_Mod(int a, int b) {return Mod(Mod(a) - Mod(b) + M);}
+inline int mul_Mod(int a, int b) {return Mod(Mod(a) * Mod(b));}
+inline int FastModExp(int a, int b) {M = mod; int res = 1; while (b > 0) {if (b & 1)res = mul_Mod(res, a); a = mul_Mod(a, a); b = b >> 1;} return res;}
+inline int mmi(int y) { return FastModExp(y, M - 2);}
+inline int div_Mod(int a, int b) { return mul_Mod(a, mmi(b));}
+inline void extendedEuclidMethod(int a, int b, int &x, int &y) { if (b == 0) {x = 1; y = 0; return;} extendedEuclidMethod(b, a % b, x, y); int cX = y; int cY = x - (a / b) * y; x = cX; y = cY;}
+
+void c_a_j()
+{
+#ifndef ONLINE_JUDGE
+    freopen("input.txt", "r", stdin);
+    freopen("output.txt", "w", stdout);
+    freopen("error.txt", "w", stderr);
+#endif
+}
+void solve()   //sliding window approach
+{
+    int n, s;
+    cin >> n >> s;
+    vector<int> v(n);
+    for (auto &x : v)cin >> x;
+    int last = 0;
+    int sum = 0, st = -1, end = -1, ans = 0;
+    for (int i = 0; i < n; i++)
+    {
+        sum += v[i];
+        while ( sum + s < 0)
+        {
+            sum -= v[last];
+            last++;
+        }
+
+        if ( ans < i - last + 1 )
+        {
+            ans = i - last + 1;
+            st = last + 1;
+            end = i + 1;
+        }
+    }
+
+    if (st == -1)
+        cout << "-1\n";
+    else
+        cout << st << " " << end << "\n";
+}
+int32_t main()
+{
+#ifdef SIEVE
+    sieve();
+#endif
+#ifdef NCR
+    init();
+#endif
+
+    FIO
+    c_a_j();
+
+    w(x)solve();
+    return 0;
+}

ExtraDSAQ/co_growing_sequence.cpp

@@ -0,0 +1,40 @@
+#include<bits/stdc++.h>
+using namespace std;
+typedef long long ll;
+const ll MOD =  1e9+7;
+#define rep(i,a,b) for(ll i=a;i<b;++i) 
+#define pii pair<int,int>
+
+int main()
+{
+    ios_base::sync_with_stdio(0);
+    cin.tie(0);
+    int tt=1;
+    cin>>tt;
+    while(tt--)
+    {
+        int n;
+        cin>>n;
+        int a[n];
+        rep(i,0,n)
+        cin>>a[i];
+        cout<<"0 ";
+        int p=a[0];
+        rep(i,1,n)
+        {
+            int c=0;
+            rep(j,0,31)
+            {
+                int t = (1<<j);
+                if(p & t)
+                {
+                    if(!(a[i]&t))
+                    c|=t,a[i]|=t;
+                }
+            }
+            cout<<c<<" ";
+            p=a[i];
+        }
+        cout<<"\n";
+    }
+}