#3160

Find the Number of Distinct Colors Among the Balls

medium · 54.2% accepted · 766 likes · top 46%

array · hash table · simulation

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Description

You are given an integer limit and a 2D array queries of size n x 2.

There are limit + 1 balls with distinct labels in the range [0, limit]. Initially, all balls are uncolored. For every query in queries that is of the form [x, y], you mark ball x with the color y. After each query, you need to find the number of colors among the balls.

Return an array result of length n, where result[i] denotes the number of colors after ith query.

Note that when answering a query, lack of a color will not be considered as a color.

Solution