feat: added leetcode 57 solution (#109)

Author: Tahanima

Algorithms/Medium/57_InsertInterval/Solution.java

@@ -0,0 +1,51 @@
+class Solution {
+    public boolean isOverlapping(int s0, int e0, int s1, int e1) {
+        if (s0 <= s1 && e0 >= e1) {
+            return true;
+        } else if (s0 >= s1 && e0 <= e1) {
+            return true;
+        } else if (e0 >= s1 && e0 <= e1) {
+            return true;
+        } else if (s0 >= s1 && s0 <= e1) {
+            return true;
+        } else {
+            return false;
+        }
+    }
+    
+    public int[][] insert(int[][] intervals, int[] newInterval) {
+        int[] tempInterval = new int[100005];
+        int minStart = newInterval[0];
+        int maxStart = newInterval[0];
+        int size = 0;
+        
+        for (int i = 0; i < 100005; tempInterval[i] = -1, i++);
+        
+        for (int[] interval: intervals) {
+            minStart = Math.min(minStart, interval[0]);
+            maxStart = Math.max(maxStart, interval[0]);
+            
+            if (isOverlapping(interval[0], interval[1], newInterval[0], newInterval[1])) {
+                newInterval[0] = Math.min(interval[0], newInterval[0]);
+                newInterval[1] = Math.max(interval[1], newInterval[1]);
+            } else {
+                tempInterval[interval[0]] = interval[1];
+                size++;
+            }
+        }
+        
+        tempInterval[newInterval[0]] = newInterval[1];
+        size++;
+        
+        int[][] answer = new int[size][2];
+
+        for (int i = minStart, j = 0; i <= maxStart; i++) {
+            if (tempInterval[i] >= 0) {
+                answer[j][0] = i;
+                answer[j++][1] = tempInterval[i];
+            }
+        }
+        
+        return answer;
+    }
+}