BZOJ3173 [Tjoi2013]最长上升子序列

[Solution]

It seems to be a abnormal data structure problem? In fact, it is not. We can easily find that answer to i = k doesn't change if you insert a number bigger than k. Therefore, you only need to get the final sequence. Then work out the LIS length of each k. Max(f[1..k]) is the answer to k.

For me, as a lazy guy, I used vector to work it out although it is very very slow.

[Code]

#include <cstdio>#include <memory.h>#include <vector>#include <algorithm>using namespace std;const int maxn = 100009;int n, f[maxn], t[maxn];vector <int> x;void btChg(int* t, int p, int v) {while (p < maxn)t[p] = max(t[p], v), p += (p & -p);}int btQry(int* t, int p) {int s = 0;while (p)s = max(s, t[p]), p -= (p & -p);return s;}int main() {memset(t, 0, sizeof(t));scanf("%d", &n);for (int i = 0; i < n; i ++) {int p;scanf("%d", &p);x. insert(x. begin() + p, i + 1);}for (vector <int> :: iterator i = x. begin(); i != x. end(); i ++) {f[*i] = btQry(t, *i) + 1;btChg(t, *i, f[*i]);}f[0] = 0;for (int i = 1; i <= n; i ++)f[i] = max(f[i - 1], f[i]), printf("%d\n", f[i]);}