HDU-1257

Code

$$O(n^2)$$的LIS

#include <bits/stdc++.h>
using namespace std;
#define _u_u_ ios::sync_with_stdio(false), cin.tie(nullptr)
#define cf int _o_o_;cin>>_o_o_;for (int Case = 1; Case <= _o_o_;Case++)
#define SZ(x) (int)(x.size())
inline void _A_A_();
signed main() {_A_A_();return 0;}

using ll = long long;
// #define int long long
const int mod = 1e9 + 7;
const int maxn = 3e4 + 10;
const int N = 210, M = 5010;
const int inf = 0x3f3f3f3f;

int a[maxn], dp[maxn];

inline void _A_A_() {
#ifdef LOCAL
freopen("in.in", "r", stdin);
#endif
_u_u_;
int n;
while (cin >> n) {
for (int i = 1;i <= n;i++) cin >> a[i];
int ans = 1;
for (int i = 1;i <= n;i++) {
dp[i] = 1;
for (int j = 1;j < i;j++) {
if(a[i] > a[j]) dp[i] = max(dp[j] + 1 , dp[i]);
}
ans = max(ans, dp[i]);
}
cout << ans << "\n";
}
}


Code

$$O(nlogn)$$的LIS，非dp，参考

#include <bits/stdc++.h>
using namespace std;
#define _u_u_ ios::sync_with_stdio(false), cin.tie(nullptr)
#define cf int _o_o_;cin>>_o_o_;for (int Case = 1; Case <= _o_o_;Case++)
#define SZ(x) (int)(x.size())
inline void _A_A_();
signed main() {_A_A_();return 0;}

using ll = long long;
// #define int long long
const int mod = 1e9 + 7;
const int maxn = 3e4 + 10;
const int N = 210, M = 5010;
const int inf = 0x3f3f3f3f;

inline void _A_A_() {
#ifdef LOCAL
freopen("in.in", "r", stdin);
#endif
_u_u_;
int n;
while (cin >> n) {
vector<int> res;    // 用来存储LIS。
int a;
for (int i = 1;i <= n;i++) {
cin >> a;
int sz = lower_bound(res.begin(),res.end(), a) - res.begin();
if (sz == SZ(res)) {
res.push_back(a);
}
else {
res[sz] = a;
}
}
cout << SZ(res) << "\n";
}
}

posted @ 2022-11-21 22:41  Sleeping_Knight  阅读(6)  评论(0编辑  收藏  举报