Create: 0006-zigzag-conversion.cpp

cpp/0006-zigzag-conversion.cpp

@@ -0,0 +1,30 @@
+/*
+    For each row the next chracter is at index 2 * (n -1) and 
+    For middle rows there will be extra characters
+    Time: O(n)
+    Space: O(1)
+*/
+class Solution {
+public:
+    string convert(string s, int n) {
+        // Edge case
+        if(n == 1) return s;
+        // Other cases
+        // Take string to store answer
+        string ans = "";
+        // We are going to traverse each row
+        for(int row = 0; row < n ; row++){
+            // for each row the next chracter is at index 2 *  (n -1) 
+            int increment = 2 *  (n -1);
+            // For first and last rows 
+            for(int i = row; i < s.length(); i+= increment){
+                ans += s[i];
+                // For middle rows there will be extra characters
+                if(row > 0 && row < n-1 && i+increment - 2 * row < s.length()){
+                    ans += s[i+increment - 2 * row];
+                }
+            }
+        }
+        return ans;
+    }
+};