Update and rename ZigzagConversion.cpp to medium-6-zigzag_conversion.cpp

Author: matthewgoembel

Codes/ZigzagConversion.cpp

@@ -0,0 +1,55 @@
+// The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)
+
+// P   A   H   N
+// A P L S I I G
+// Y   I   R
+
+// And then read line by line: "PAHNAPLSIIGYIR"
+
+// Write the code that will take a string and make this conversion given a number of rows:
+
+// string convert(string s, int numRows);
+ 
+
+// Example 1:
+
+// Input: s = "PAYPALISHIRING", numRows = 3
+// Output: "PAHNAPLSIIGYIR"
+
+// Example 2:
+
+// Input: s = "PAYPALISHIRING", numRows = 4
+// Output: "PINALSIGYAHRPI"
+// Explanation:
+// P     I    N
+// A   L S  I G
+// Y A   H R
+// P     I
+
+// Example 3:
+
+// Input: s = "A", numRows = 1
+// Output: "A"
+
+
+class Solution {
+public:
+    string convert(string s, int numRows) {    
+    if(numRows <= 1) 
+        return s;
+    vector<string>v(numRows, "");
+    int j = 0, dir = -1;
+    for(int i = 0; i < s.length(); i++){
+        if(j == numRows - 1 || j == 0) 
+            dir *= (-1);		 
+        v[j] += s[i];
+        if(dir == 1) 
+            j++;
+        else j--;
+    }
+    string res;
+    for(auto &it : v) 
+        res += it; 
+    return res;
+    }
+};