CodeChef : June Challenge 2017 – Xenny and Coin Rankings

By | June 5, 2017
Xenny and Coin Rankings

Source: CodeChef

Xenny reverse-engineered all the binaries released by the International Security Agency (ISA) during summer vacation just to pass time. As a reward, the ISA gave him infinite ByteCoins.

Out of sheer boredom and a sense of purposelessness in life, Xenny decided to arrange the Coins on a 2-Dimensional Euclidean Plane. The boredom was so strong that he arranged these coins in a specific pattern, as opposed to the usual, monotonous way of storing coins in a Piggy Bank.

On each integer co-ordinate (x, y) where x ≥ 0 and y ≥ 0, a single coin was placed. And each coin was assigned a rank. The following pattern was followed in the arrangement:

Let’s denote the co-ordinates of the kth coin by (xk, yk) and its rank by Rk.

For any 2 coins i, j:

if (xi + yi) < (xj + yj) or ( (xi + yi) == (xj + yj) and xi < xj)

then Ri < Rj. We sort all the coins by this comparison.

The index of the coin (C) in this sorted list of coins (1-indexed) is its rank.

Each query is as follows: Given (U, V). Among the coins that are lying on or inside the rectangle with its diagonal end-points being (0, 0) and (U, V), which is the coin that has the maximum rank?


The first line contains an integer, T – the number of testcases.

Each testcase contains 2 space-separated integers: U, V.


For each testcase, print the rank of the maximum ranked coin, on a new line.


Subtask 1: (40 points)

  • 1 ≤ T ≤ 100
  • 1 ≤ U, V ≤ 100

Subtask 2: (60 points)

  • 1 ≤ T ≤ 100
  • 1 ≤ U, V ≤ 109

Sample Testcase

1 2



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