Add files via upload

Author: MathProgrammer

2020/Div 2/616 Div 2/Programs/Array Sharpening.cpp

@@ -0,0 +1,80 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+void solve()
+{
+    int no_of_elements;
+    cin >> no_of_elements;
+    
+    vector <int> A(no_of_elements + 1);
+    for(int i = 1; i <= no_of_elements; i++)
+    {
+        cin >> A[i];
+    }
+    
+    vector <int> prefix_possible(no_of_elements + 1, false);
+    for(int i = 1; i <= no_of_elements; i++)
+    {
+        if(A[i] < i - 1)
+        {
+            break;
+        }
+        
+        prefix_possible[i] = true;
+    }
+    
+    vector <int> suffix_possible(no_of_elements + 1, false);
+    for(int i = no_of_elements; i >= 1; i--)
+    {
+        if(A[i] < (no_of_elements - i))
+        {
+            break;
+        }
+        
+        suffix_possible[i] = true;
+    }
+    
+    int possible = (no_of_elements == 1 ? true : false);
+    
+    for(int i = 1; i <= no_of_elements; i++)
+    {
+        if(i == 1)
+        {
+            if(A[i] >= (no_of_elements - i) && suffix_possible[i + 1])
+            {
+                possible = true;
+                break;
+            }
+        }
+        
+        if(i == no_of_elements)
+        {
+            if(A[i] >= (i - 1) && prefix_possible[i - 1])
+            {
+                possible = true;
+                break;
+            }
+        }
+        
+        if(A[i] >= (i - 1) && prefix_possible[i - 1] && A[i] >= (no_of_elements - i) && suffix_possible[i + 1])
+        {
+            possible = true;
+            break;
+        }
+    }
+    
+    cout << (possible ? "Yes\n" : "No\n");
+}
+
+int main()
+{
+    int no_of_test_cases;
+    cin >> no_of_test_cases;
+    
+    while(no_of_test_cases--)
+        solve();
+    
+    return 0;
+}

2020/Div 2/616 Div 2/Programs/Even But Not Even.cpp

@@ -0,0 +1,46 @@
+#include <iostream>
+
+using namespace std;
+
+void solve()
+{
+    int length;
+    string S;
+    
+    cin >> length >> S;
+    
+    int odd_count = 0;
+    for(int i = 0; i < length; i++)
+    {
+        odd_count += (S[i] - '0')%2;
+    }
+    
+    if(odd_count < 2)
+    {
+        cout << "-1\n";
+        
+        return;
+    }
+    
+    string answer;
+    for(int i = 0; i < length && answer.size() < 2; i++)
+    {
+        if( (S[i] - '0')%2 == 1)
+        {
+            answer += S[i];
+        }
+    }
+    
+    cout << answer << "\n";
+}
+
+int main()
+{
+    int no_of_test_cases;
+    cin >> no_of_test_cases;
+    
+    while(no_of_test_cases--)
+        solve();
+    
+    return 0;
+}