searching-sorting added

04_searching_and_sorting/10_find_pair_with_given_diff.cpp

@@ -0,0 +1,77 @@
+/*
+    link: https://practice.geeksforgeeks.org/problems/find-pair-given-difference1559/1
+*/
+
+// ----------------------------------------------------------------------------------------------------------------------- //
+/*
+    sliding window
+*/
+bool findPair(int arr[], int size, int n)
+{
+    sort(arr, arr + size);
+    int i = 0;
+    int j = 1;
+
+    while (i < size && j < size)
+    {
+        if (i != j && arr[j] - arr[i] == n)
+        {
+            return true;
+        }
+        else if (arr[j] - arr[i] < n)
+            j++;
+        else
+            i++;
+    }
+
+    return false;
+}
+
+
+
+// ----------------------------------------------------------------------------------------------------------------------- //
+/*
+    using hashSet
+    TC: O(n)
+    SC: O(n)
+*/
+bool findPair(int arr[], int size, int n) {
+    //code
+    unordered_set<int> s;
+    for (int i = 0;i < size;i++) {
+        s.insert(arr[i]);
+    }
+
+    for (int i = 0;i < size;i++) {
+        int toFindMax = arr[i] + n;
+        int toFindMin = arr[i] - n;
+
+        if (s.find(toFindMax) != s.end() || s.find(toFindMin) != s.end()) {
+            return true;
+        }
+
+    }
+    return false;
+}
+
+
+
+
+// ----------------------------------------------------------------------------------------------------------------------- //
+/*
+    using recursion
+*/
+bool recur(int arr[], int n, int left, int right) {
+    if (left >= right) return false;
+
+    int diff = arr[right] - arr[left];
+    if (diff == n) return true;
+
+    return recur(arr, n, left + 1, right) | recur(arr, n, left, right - 1);
+}
+
+bool findPair(int arr[], int size, int n) {
+    //code
+    sort(arr, arr + size);
+    int right = size - 1, left = 0;
+    return recur(arr, n, left, right);