2018-05-01 11:10:54
本文介绍了输入数据规模和时间复杂度上限的关系，可以通过数据规模推算使用算法的类型。
- < 10: O(n!) permutation
- < 15: O(2^n) combination
- < 50: O(n^4) DP
- < 200: O(n^3) DP, all pairs shortest path
- < 1,000: O(n^2) DP, all pairs, dense graph
- < 1,000,000: O(nlogn), sorting-based (greedy), heap, divide & conquer
- < 1,000,000: O(n), DP, graph traversal / topological sorting (V+E), tree traversal
- < INT_MAX: O(sqrt(n)), prime, square sum
- < INT_MAX: O(logn), binary search
- < INT_MAX: O(1) Math