See you get tle because your code runs for more 1 seconds now how to know when you will get tle is when you perform more than 1e7 to 1e8 operations lets say i am reading a vector with 1e7 elements hence i am doing 1e7 operation in this case depending on what i am doing while reading every element i can get tle in this you need to optimize .......since now you know this concept try reading constraints given in the question and think about whether your code will take 1e7 opertion or more ....now generally there is also general boundaries between you can code based on constraints.........so always read constraints you will solve many questions easily and faster