LEVEL 2 | STLs 2

Facebook: https://www.facebook.com/FUICPC Slides: https://bit.ly/3uK1Q0l Anton and Letters: https://codeforces.com/problemset/problem/443/A Solution: https://codeforces.com/contest/443/submission/247391528 Two-gram: https://codeforces.com/problemset/problem/977/B Solution: https://codeforces.com/contest/977/submission/247393226 SORT2D - 2D-SORT: https://www.spoj.com/problems/SORT2D/en/ Solution: https://ideone.com/y09KLp https://ideone.com/4V1gc8 Dawid and Bags of Candies: https://codeforces.com/problemset/problem/1230/A: Solution: https://codeforces.com/contest/1230/submission/247396477 Registration system: https://codeforces.com/problemset/problem/4/C Solution: https://codeforces.com/contest/4/submission/247395548 STL Containers reference: https://cplusplus.com/reference/stl/