1

Part of 2012 Germany Team Selection Test

Problems(1)

Least Changes to Make Sums Different

Source: Germany TST 2012 P1

Find the least integer

k

such that for any

2011 \times 2011

table filled with integers Kain chooses, Abel be able to change at most

k

cells to achieve a new table in which

4022

sums of rows and columns are pairwise different.