Added solution

Author: avidLearnerInProgress

increasing_triplet_subsequence.cpp

@@ -0,0 +1,16 @@
+class Solution {
+public:
+    bool increasingTriplet(vector<int>& nums) {
+        
+        int min_ = INT_MAX, nmin_ = INT_MAX;
+            
+        for(auto num : nums){
+            min_ = min(min_, num);
+            if(num > min_)
+                nmin_ = min(nmin_, num);
+            if(num > nmin_)
+                return true;
+        }
+        return false;
+    }
+};