class Solution {
public:
bool increasingTriplet(vector<int>& nums) {
int N = nums.size();
if(N<3) return false;
int a,b;
a = b = INT_MAX;
for(int i=0;i<N;i++){
if(nums[i]>b) return true;
if(nums[i]>a) b = nums[i];
else a = nums[i];
}
return false;
}
};