组合题6 个小题
已作答 0 / 6
1#include <algorithm>2#include <iostream>3using namespace std;4 5int n, a[1005];6 7struct Node8{9 int h, j, m, w;10 11 Node(const int _h, const int _j, const int _m, const int _w):12 h(_h), j(_j), m(_m), w(_w)13 { }14 15 Node operator+(const Node &o) const16 {17 return Node(18 max(h, w + o.h),19 max(max(j, o.j), m + o.h),20 max(m + o.w, o.m),21 w + o.w);22 }23};24 25Node solve1(int h, int m)26{27 if (h > m)28 return Node(-1, -1, -1, -1);29 if (h == m)30 return Node(max(a[h], 0), max(a[h], 0), max(a[h], 0), a[h]);31 int j = (h + m) >> 1;32 return solve1(h, j) + solve1(j + 1, m);33}34 35int solve2(int h, int m)36{37 if (h > m)38 return -1;39 if (h == m)40 return max(a[h], 0);41 int j = (h + m) >> 1;42 int wh = 0, wm = 0;43 int wht = 0, wmt = 0;44 for (int i = j; i >= h; i--) {45 wht += a[i];46 wh = max(wh, wht);47 }48 for (int i = j + 1; i <= m; i++) {49 wmt += a[i];50 wm = max(wm, wmt);51 }52 return max(max(solve2(h, j), solve2(j + 1, m)), wh + wm);53}54 55int main()56{57 cin >> n;58 for (int i = 1; i <= n; i++) cin >> a[i];59 cout << solve1(1, n).j << endl;60 cout << solve2(1, n) << endl;61 return 0;62}假设输入的所有数的绝对值都不超过 1000 ,完成下面的判断题和单选题:
solve1(1, n) 的时间复杂度为( )。