洛谷-1052

思路

文字版

视频版

Code

#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
int mod = 1e9 + 7;
const int maxn = 1e5 + 30;
const int N = 210, M = 5010;
const int inf = 0x3f3f3f3f;

int f[maxn], w[maxn], stone[maxn];

inline void _A_A_() {
    #ifdef LOCAL
    freopen("in.in", "r", stdin);
    #endif
    _u_u_;
    int L;
    cin >> L;
    int s, t, m;
    cin >> s >> t >> m;
    for (int i = 1;i <= m;i++) {
        cin >> stone[i];
    }
    sort(stone + 1, stone + 1 + m);
    if (s == t) {
        int res = 0;
        for (int i = 1;i <= m;i++) {
            if (stone[i] % s == 0) res++;
        }
        cout << res << "\n";
        return;
    }
    else {
        int last = 0;
        int d = 0;
        for (int i = 1;i <= m;i++) {
            if (stone[i] - last >= 80) {
                d += stone[i] - last - 80;
            }
            last = stone[i];
            stone[i] -= d;
        }
        for (int i = 1;i <= m;i++) w[stone[i]] = 1;
        L = stone[m] + 10;
        for (int i = 1;i <= L;i++) {
            f[i] = inf;
            for (int j = s;j <= t;j++) {
                if (i - j >= 0) f[i] = min(f[i], f[i - j] + w[i]);
            }
        }
        cout << f[L] << "\n";
    }

}