From now on, I will add some topic wise problems which I face regularly. I think it will help new commers like me. Thank you :)
1.Cumulative sum/ prefix sum :
(https://codeforces.me/problemset/problem/363/B)
(https://codeforces.me/problemset/problem/313/B)
(https://codeforces.me/problemset/problem/1363/B)
(https://codeforces.me/problemset/problem/433/B)
(https://codeforces.me/problemset/problem/296/C)
(https://codeforces.me/problemset/problem/816/B)
(https://codeforces.me/problemset/problem/1341/B)
(https://codeforces.me/problemset/problem/961/B)
(https://codeforces.me/problemset/problem/276/C)
(https://codeforces.me/problemset/problem/1678/B1)
(https://codeforces.me/problemset/problem/1678/B1)
(https://www.spoj.com/problems/CSUMQ/en/)
(https://www.spoj.com/problems/RANGESUM/en/)
(https://www.codechef.com/problems/QUALPREL)
(https://www.codechef.com/problems/PTMSSNG)
(https://www.codechef.com/problems/MEX)
(https://www.codechef.com/problems/PTMSSNG)
(https://www.eolymp.com/en/problems/6959)
(https://onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=924)
Here are some Binary search related problems
2.Binary Search
(https://codeforces.me/problemset/problem/474/B)
(https://lightoj.com/problem/points-in-segments)
(https://lightoj.com/problem/counting-triangles)
(https://lightoj.com/problem/points-in-segments-ii)
(https://lightoj.com/problem/crossed-ladders)
(https://www.spoj.com/problems/EKO/)
(https://www.spoj.com/problems/PIE/)(https://www.spoj.com/problems/AGGRCOW/)
(https://www.codechef.com/problems/MINEAT)
(https://www.interviewbit.com/problems/painters-partition-problem/)
(https://codeforces.me/problemset/problem/230/B)
(https://codeforces.me/problemset/problem/474/B)
3. Even Odd integers counting in a range inclusive [l,r]:
Numbers of even integers is a range inclusive [l,r] = (r/2)-(l-1)/2
Numbers of odd integers is a range inclusive [l,r] = (r-l+1)-( (r/2)-(l-1)/2 ) Practice: https://codeforces.me/problemset/problem/1629/B
4. STL: MAP
(https://practice.geeksforgeeks.org/problems/find-the-frequency/1)
(https://practice.geeksforgeeks.org/problems/twice-counter4236/1)
(https://practice.geeksforgeeks.org/problems/word-with-maximum-frequency0120/1)
(https://atcoder.jp/contests/arc087/tasks/arc087_a)
(https://codeforces.me/contest/918/problem/B)
(https://www.spoj.com/problems/RPLD/)
(https://codeforces.me/contest/855/problem/A)
(https://codeforces.me/contest/4/problem/C)
(https://codeforces.me/contest/903/problem/C)
SET:
(https://codeforces.me/contest/558/problem/E)
(https://codeforces.me/problemset/problem/567/D)
(https://codeforces.me/contest/528/problem/A)
(https://codeforces.me/problemset/problem/22/A)
0 1 knapsack DP:
Thank you :)