Merge pull request #419 from m-oliv/patch-1

- Added the reverse integer algo.

CONTRIBUTORS.md

@@ -1,4 +1,4 @@
-Name: [Miftahul J.](https://github.com/jiadibo)<br/>
+Name: [Miftahul J.](https://github.com/jiadibo)<br/>
 Place: Indonesia<br/>
 About: I'm moslem programmer<br/>
 Programming Language: Java, kotlin, flutter<br/>
@@ -63,6 +63,7 @@ About: I am 3rd yearComputer science student at poornima college of engineering,
 Programming Languages: C, C++,python</br>
 
 
+
 Name: [Henry McCreery](github.com/hmccree)
 Place: Portland, Oregon, USA
 About: High school robotics team member project manager
@@ -395,22 +396,26 @@ About: I am a sophomore at IIT Mandi<br/>
 Programming Languages: C, C++, JavaScript<br/>
 Email: [email protected]
 
+
 Name: [Samyak](https://github.com/samyak-sopho)
 Place: Allahabad
 About: Will do anything for free shirt
 Programming Language: C++, JS, Java
 
+
 Name: [Marlene Oliveira](https://github.com/m-oliv)
 Place: Lisbon, Portugal
 About: Software Engineer
 Programming Language: Java, C, C#, Python, JavaScript, HTML, CSS
 
+
 Name: [Trevin Edinger](https://github.com/ArkTrevelyan)
 Place: Elkins, WV, USA
 About: High School Graduate. Self teaching to be a programmer.
 Programming Languages: Java, C.
 Email: [email protected]
 
+
 Name: [Tsaruk Alex](https://github.com/WildTiger404)<br/>
 Place: Minsk, Belarus<br/>
 About: I am a 3rd year stundent. I like traveling and events like this one<br/>
@@ -423,6 +428,7 @@ About: I am a 3rd Year Computer Science student at JSSATE Noida<br/>
 Programming Languages: C, Java<br/>
 Email: [email protected]
 
+
 Name: [Darshan D V](https://github.com/darshandv)<br/>
 Place: Mangalore, Karnataka ,India<br/>
 About: I am a Computer Science student at NITK Surathkal<br/>
@@ -435,6 +441,7 @@ About: Btech student from JIIT<br/>
 Programming Languages: C,C++,python3<br/>
 email: [email protected]<br/>
 
+
 Name: [Kartik Singh](https://github.com/Kartik212112)<br/>
 Place: Patna,India<br/>
 About: Btech student from IITP<br/>
@@ -705,4 +712,5 @@ Programming Languages: php, java, javascript<br />
 Name: [Felipe](https://github.com/ja1felipe)<br/>
 Place: Brazil<br/>
 About: I am studying computer science.<br/>
-Programming Language:Python, java<br/>
+Programming Language:Python, java<br/>
+

reverse/ReverseInteger.java

@@ -0,0 +1,26 @@
+class ReverseInteger {
+    public static int reverse(int x) {
+        int reversed = 0;
+        int y = 0;
+
+        while(x!=0){
+            reversed = y * 10 + x % 10;
+            if((reversed - x % 10)/10 == y) {
+                y = reversed;
+            }else {
+                return 0;
+            }
+            x = x/10;
+        }
+
+        if(x < 0) {
+            return y * -1;
+        }
+
+        return y;
+  }
+
+  public static void main(String[] args) {
+    System.out.println(reverse(12345));
+  }
+}

sorting/mergesort.go

@@ -0,0 +1,58 @@
+package main
+
+import (
+    "fmt"
+)
+
+func main() {
+    A := []int{3, 5, 1, 6, 1, 7, 2, 4, 5}
+    fmt.Println(sort(A))
+}
+
+// top-down approach
+func sort(A []int) []int {
+    if len(A) <= 1 {
+        return A
+    }
+
+    left, right := split(A)
+    left = sort(left)
+    right = sort(right)
+    return merge(left, right)
+}
+
+// split array into two
+func split(A []int) ([]int, []int) {
+    return A[0:len(A) / 2], A[len(A) / 2:]
+}
+
+// assumes that A and B are sorted
+func merge(A, B []int) []int {
+    arr := make([]int, len(A) + len(B))
+
+    // index j for A, k for B
+    j, k := 0, 0
+
+    for i := 0; i < len(arr); i++ {
+        // fix for index out of range without using sentinel
+        if j >= len(A) {
+            arr[i] = B[k]
+            k++
+            continue
+        } else if k >= len(B) {
+            arr[i] = A[j]
+            j++
+            continue
+        }
+        // default loop condition
+        if A[j] > B[k] {
+            arr[i] = B[k]
+            k++
+        } else {
+            arr[i] = A[j]
+            j++
+        }
+    }
+
+    return arr
+}