https://codeforces.me/problemset/problem/177/C1 please help how to solve this question thanks in advance

https://codeforces.me/contest/1220/submission/122950923 i have tried this a lot but still not able to remove TLE in case of input n is 10^3 so automatically input will be o(n^2) so how to do it?? thanks in advance

http://codeforces.me/contest/126/problem/B i have tried to solve this problem but it gave runtime error on 26 th tc https://codeforces.me/contest/126/submission/120644479 please help thanks in advance

https://codeforces.me/contest/1485/submission/118904427 i have tried a lot still dont get my mistake please help ,why it is wrong ans in which type of test cases it will not work

https://codeforces.me/contest/20/submission/114756156 i am unable to find mistake please help thanks in advance

https://codeforces.me/contest/820/submission/82782140 i didnot get what is the error in logic what does they mean by better answer?please help thanks in advance

https://codeforces.me/contest/1291/problem/B Please help I am unable to approach this problem have seen several solution as well as editorial but failed to understand 1)why a[I]>I??what will happen if this not take place? 2)why there checking a[n-i-1] with the value n-i-1 ??what is the use of prefix array and suffix end array??