Solutions to Hackerrank Problems.

hackerrank_solutions_intro+strings/Arrays.cpp

@@ -0,0 +1,21 @@
+#include <cmath>
+#include <cstdio>
+#include <vector>
+#include <iostream>
+#include <algorithm>
+using namespace std;
+
+
+int main() {
+    int n;
+    cin >> n;
+    int a[n];
+    for (int i = 0; i < n; i++){
+        cin >> a[i] ;
+
+    }
+    for (int i = n-1 ; i >= 0 ; i--){
+        cout << a[i] << " ";
+    }
+    return 0;
+}

hackerrank_solutions_intro+strings/Conditionals.cpp

@@ -0,0 +1,18 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int main(){
+    int n;
+    cin >> n;
+    if (n == 1) cout << "one" << endl;
+    else if (n == 2) cout << "two" << endl;
+    else if (n == 3) cout << "three" << endl;
+    else if (n == 4) cout << "four" << endl;
+    else if (n == 5) cout << "five" << endl;
+    else if (n == 6) cout << "six" << endl;
+    else if (n == 7) cout << "seven" << endl;
+    else if (n == 8) cout << "eight" << endl;
+    else if (n == 9) cout << "nine" << endl;
+    else cout << "Greater than 9" << endl;
+}
+

hackerrank_solutions_intro+strings/Data_Types.cpp

@@ -0,0 +1,31 @@
+#include <cmath>
+#include <cstdio>
+#include <vector>
+#include <iostream>
+#include <algorithm>
+using namespace std;
+
+
+int main() {
+    /* Enter your code here. Read input from STDIN. Print output to STDOUT */ 
+    int i;
+    long l;
+    char cr;
+    char spa;
+    float ft;
+     double db;
+     scanf("%d",&i);
+     scanf("%ld\n",&l);
+     //scanf("%c",&spa);
+     scanf("%c",&cr);
+
+     scanf("%f",&ft);
+     scanf("%lf",&db);
+     printf("%d\n",i);
+     printf("%ld\n",l);
+     printf("%c\n",cr);
+     printf("%.3f\n",ft);
+     printf("%.9lf\n",db);
+
+    return 0;
+}

hackerrank_solutions_intro+strings/For_Loop.cp

@@ -0,0 +1,28 @@
+#include <iostream>
+#include <cstdio>
+using namespace std;
+
+int main() {
+    // Complete the code.
+    int a, b;
+    cin >> a >> b;
+    for (int i = a; i <= b ; i++){
+        if (i <= 9){
+            if (i == 1) cout << "one" << endl;
+            else if (i == 2) cout << "two" << endl;
+            else if (i == 3) cout << "three" << endl;
+            else if (i == 4) cout << "four" << endl;
+            else if (i == 5) cout << "five" << endl;
+            else if (i == 6) cout << "six" << endl;
+            else if (i == 7) cout << "seven" << endl;
+            else if (i == 8) cout << "eight" << endl;
+            else cout << "nine" << endl;
+
+        }
+        else {
+            if (i%2 == 0) cout << "even" << endl;
+            else cout << "odd" << endl;
+        }
+    }
+    return 0;
+}

hackerrank_solutions_intro+strings/Functions.cpp

@@ -0,0 +1,38 @@
+#include <iostream>
+#include <cstdio>
+using namespace std;
+
+/*
+Add `int max_of_four(int a, int b, int c, int d)` here.
+*/
+void max_of_four(int a, int b, int c, int d){
+    if(a > b){
+        if (a > c){
+            if (a > d) cout <<  a ;
+            else cout <<  d;
+        }
+        else{
+            if (c > d) cout <<  c;
+            else cout << d;
+        } 
+    }
+    else {
+         if (b > c){
+            if (b > d) cout << b;
+            else cout <<  d;
+        }
+         else{
+            if (c > d) cout << c;
+            else cout << d;
+        } 
+    }
+}
+
+int main() {
+    int a, b, c, d;
+    cin >> a >> b >> c >> d;
+    max_of_four(a,  b, c,  d);
+    cout << endl;
+
+    return 0;
+}

hackerrank_solutions_intro+strings/Hello_World.cpp

@@ -0,0 +1,8 @@
+#include <iostream>
+#include <cstdio>
+using namespace std;
+
+int main() {
+    printf("Hello, World!");
+    return 0;
+}

hackerrank_solutions_intro+strings/Input_Output.cpp

@@ -0,0 +1,17 @@
+#include <cmath>
+#include <cstdio>
+#include <vector>
+#include <iostream>
+#include <algorithm>
+using namespace std;
+
+
+int main() {
+    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
+    int a, b, c;
+    cin >> a >> b >> c;
+    int sum;
+    sum = a + b + c;
+    cout << sum << endl;
+    return 0;
+}

hackerrank_solutions_intro+strings/Pointers.cpp

@@ -0,0 +1,11 @@
+#include <iostream>
+using namespace std;
+int main() {
+    int a, b;
+    cin >> a >> b;
+    int x = a + b;
+    int y = a - b;
+    int z = abs(y);
+    cout << x << endl << z << endl;
+    return 0;
+}

hackerrank_solutions_intro+strings/StringStream.cpp

@@ -0,0 +1,25 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+vector<int> parseInts(string str) {
+	// Complete this function
+    vector<int> parse;
+    stringstream ss(str);
+    int t;
+    char c;
+    while(ss >> t){
+        parse.push_back(t);
+        ss >> c;
+    }
+    return parse;
+}
+
+int main() {
+    string str;
+    cin >> str;
+    vector<int> integers = parseInts(str);
+    for(int i = 0; i < integers.size(); i++) {
+        cout << integers[i] << "\n";
+    }
+    return 0;
+}

hackerrank_solutions_intro+strings/Strings.cpp

@@ -0,0 +1,20 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    // Complete the program
+    string a, b;
+    cin >> a;
+    cin >> b;
+    int c, d;
+    c = a.size();
+    d = b.size();
+    cout << c << " " << d << endl;
+    string x = a + b;
+    cout << x << endl;
+    char ch = a[0];
+    a[0] = b[0];
+    b[0] = ch;
+    cout << a << " " << b << endl;
+    return 0;
+}

hackerrank_solutions_intro+strings/Variable_Size_Arrays.cpp

@@ -0,0 +1,29 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    int n, q;
+    cin >> n >> q;
+    vector<int> k(n); 
+    vector<vector<int>> a(n); 
+    for (int i = 0; i < n; i++){
+        cin >> k[i];
+        a[i].resize(k[i]); 
+        //took help from gfg for this...
+        for(int j = 0 ; j < k[i]; j++){
+            cin >> a[i][j];
+        }
+    }
+
+    vector<vector<int>> que(q, vector<int>(2)); 
+    for (int i = 0; i < q; i++){
+        for (int j = 0 ; j < 2 ; j++){
+            cin >> que[i][j];
+        }
+    } 
+    for (int i = 0; i < q; i++){
+        cout << a[que[i][0]][que[i][1]] << endl;
+    }
+
+    return 0;
+}