MathDB
Easy inequality with integer variable

Source: China Additional TST for IMO 2020, P5

October 20, 2020
inequalitiesalgebra

Problem Statement

Let a1,a2,,ana_1,a_2,\cdots,a_n be a permutation of 1,2,,n1,2,\cdots,n. Among all possible permutations, find the minimum of i=1nmin{ai,2i1}.\sum_{i=1}^n \min \{ a_i,2i-1 \}.