E - Array Shrinking,区间dp,Educational Codeforces Round 83 (Rated for Div. 2)
E-ArrayShrinking,EducationalCodeforcesRound83(RatedforDiv.2)http://codeforces.com/contest/1312/problem/EYouaregivenanarraya1,a2,…,an.Youcanperformthefollowingoperationanynumberoftimes:Chooseapairoftwo