Added solutions to 4 more problems

14.cpp

@@ -0,0 +1,31 @@
+# include <bits/stdc++.h>
+
+using namespace std;
+
+int main() {
+    int v, e, x, y;
+    cin>>v>>e;
+    list <int> ar[v], q; // store graph as adjacency list, visited nodes to be pushed into q
+    bool visited[v]; // boolean array to keep track of visited vertices
+    for (int i = 0; i < v; ++i)
+        visited[i] = 0; // set all vertices as unvisited
+    for (int i = 0; i < e; ++i) {
+        cin>>x>>y;
+        ar[x].push_back(y);
+    }
+    q.push_back(0);
+    visited[0] = 1; // visit first node 0
+    int s;
+    while (!q.empty()) { // BFS Code
+        s = q.front();
+        cout<<s<<" ";
+        q.pop_front();
+        for (list<int>::iterator it = ar[s].begin(); it != ar[s].end(); ++it) { // iterate through all the adjacent vertices of vertice s
+            if (!visited[*it]) {
+                q.push_back(*it); // add vertice to q if not previously visited
+                visited[*it] = 1;
+            }
+        }
+    }
+    return 0;
+}

16.cpp

@@ -0,0 +1,34 @@
+# include <bits/stdc++.h>
+
+using namespace std;
+
+int main() {
+    char str[100];
+    int N, n[3] = {0, 0, 0}; // To keep track of how many parentheses have been opened/closed
+    cin>>N;
+    for (int a = 0; a < N; ++a) {
+        cin>>str;
+        for (int i = 0; str[i] != '\0'; ++i) {
+            switch (str[i]) {
+                case '{':   n[0] += 1; // Parentheses open
+                            break;
+                case '(':   n[1] += 1;
+                            break;
+                case '[':   n[2] += 1;
+                            break;
+                case '}':   n[0] -= 1; //Parentheses close
+                            break;
+                case ')':   n[1] -= 1;
+                            break;
+                case ']':   n[2] -= 1;
+                            break;
+            }
+        }
+        if (n[0] == 0 && n[1] == 0 && n[2] == 0) // Check whether parentheses are valid
+            cout<<"YES"<<endl;
+        else
+            cout<<"NO"<<endl;
+    }
+
+
+}

17.py

@@ -0,0 +1,8 @@
+from itertools import permutations
+
+ar = list(map(int, str(input()).split())) # store digits in a list as integers
+
+perms = list(permutations(ar + [ar[0]])) + list(permutations(ar + [ar[1]])) + list(permutations(ar + [ar[2]])) # generate all permutations of the pass code
+
+for i in set(perms): # set to remove possible duplicates
+    print (''.join(str(j) for j in i))

3.cpp

@@ -0,0 +1,26 @@
+# include <bits/stdc++.h>
+
+using namespace std;
+
+int main() {
+    int t, n;
+    cin>>t;
+    for (int i = 0; i < t; ++i){
+        cin>>n;
+        int ar[n], sum = 0;
+        for (int j = 0; j < n; ++j){
+            cin>>ar[j];
+            sum += ar[j];
+        }
+        for (int i1 = 0; i1 < n; ++i1) // starting index of sub array
+            for (int i2 = n - 1; i2 >= i1; --i2) { // ending index of sub array
+                int sub_sum = 0;
+                for (int k = i1; k <= i2; k++) // sum the sub array
+                    sub_sum += ar[k];
+                if (sub_sum > sum)
+                    sum = sub_sum;
+            }
+        cout<<sum<<endl;
+    }
+    return 0;
+}