Educational Codeforces Round 95 (Rated for Div. 2)

A

#include <bits/stdc++.h>
#define all(n) (n).begin(), (n).end()
#define se second
#define fi first
#define pb push_back
#define mp make_pair
#define sqr(n) (n)*(n)
#define rep(i,a,b) for(int i=(a);i<=(b);++i)
#define per(i,a,b) for(int i=(a);i>=(b);--i)
#define IOS ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr)
using namespace std;
typedef unsigned long long ull;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;
typedef vector<int> VI;
typedef double db;
 
const int N = 1e5 + 5;
 
int n, m, _, k;
int a[N];
 
int main() {
    IOS;
    for (cin >> _; _; --_) {
        ll n, m, k; cin >> n >> m >> k;
        cout << ((k * (m + 1) - 2) / (n - 1) + 1 + k) << '\n';
    }
    return 0;
}

B

贪心

#include <bits/stdc++.h>
#define all(n) (n).begin(), (n).end()
#define se second
#define fi first
#define pb push_back
#define mp make_pair
#define sqr(n) (n)*(n)
#define rep(i,a,b) for(int i=(a);i<=(b);++i)
#define per(i,a,b) for(int i=(a);i>=(b);--i)
#define IOS ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr)
using namespace std;
typedef unsigned long long ull;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;
typedef vector<int> VI;
typedef double db;
 
const int N = 1e5 + 5;
 
int n, m, _, k;
int a[N], b[N], s[N];
 
int main() {
    IOS;
    for (cin >> _; _; --_) {
        cin >> n; VI v;
        rep (i, 1, n) cin >> a[i], s[i] = s[i - 1] + a[i];
        rep (i, 1, n) {
            cin >> b[i];
            if (!b[i]) v.pb(a[i]);
        }
        sort(all(v));
 
        rep (i, 1, n)
            if (!b[i]) cout << v.back() << ' ', v.pop_back();
            else cout << a[i] << ' ';
        cout << '\n';      
    }
    return 0;
}

C

dp, 三位, 第一维是第 i 个怪兽, j 你的朋友杀了几只怪取(1, 2), k 你杀了几只怪(可取 0, 1, 2)

#include <bits/stdc++.h>
#define all(n) (n).begin(), (n).end()
#define se second
#define fi first
#define pb push_back
#define mp make_pair
#define sqr(n) (n)*(n)
#define rep(i,a,b) for(int i=(a);i<=(b);++i)
#define per(i,a,b) for(int i=(a);i>=(b);--i)
#define IOS ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr)
using namespace std;
typedef unsigned long long ull;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;
typedef vector<int> VI;
typedef double db;
 
const int N = 2e5 + 5;
 
int n, m, _, k;
int a[N], f[N][3][3];
 
int main() {
    IOS;
    for (cin >> _; _; --_) {
        cin >> n;
        rep (i, 0, n) memset(f[i], 0x3f, sizeof f[i]);
        f[0][2][2] = 0;
        rep (i, 1, n) {
            cin >> a[i];
            f[i][1][0] = min(f[i - 1][1][1], min(f[i - 1][1][2], f[i - 1][2][2])) + a[i];
            f[i][1][1] = f[i - 1][1][0];
            f[i][1][2] = f[i - 1][1][1];
            f[i][2][0] = f[i - 1][1][0] + a[i];
            f[i][2][1] = f[i - 1][2][0];
            f[i][2][2] = f[i - 1][2][1]; 
        }
        int ans = 1e9;
        rep (i, 1, 2) rep (j, 0, 2) ans = min(f[n][i][j], ans);
        cout << ans << '\n';
    }
    return 0;
}

D

stl的应用, 模拟就完事

#include <bits/stdc++.h>
#define all(n) (n).begin(), (n).end()
#define se second
#define fi first
#define pb push_back
#define mp make_pair
#define sqr(n) (n)*(n)
#define rep(i,a,b) for(int i=(a);i<=(b);++i)
#define per(i,a,b) for(int i=(a);i>=(b);--i)
#define IOS ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr)
using namespace std;
typedef unsigned long long ull;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;
typedef vector<int> VI;
typedef double db;

const int N = 2e5 + 5;

int n, m, _, k;
ll s = 0;
set<int> st;
map<int, int> sum;

void check(int x) {
    if (sum[x] == 0) sum.erase(x);
}

void insert(int x) {
    if (st.empty()) { st.insert(x); return; }
    auto it = st.insert(x).fi;
    auto be = it, af = it;
    if (it != st.begin()) --be;
    if (af != --st.end()) ++af;
    //cout << *be << ' ' << x << ' ' << *af << '\n';
    if (af == it) ++sum[x - *be], s += x - *be;
    else if (it == be) ++sum[*af - x], s += *af - x;
    else ++sum[x - *be], ++sum[*af - x], --sum[*af - *be], check(*af - *be);
}

void delet(int x) {
    if (st.size() == 1) { st.clear(); return; }
    auto it = st.find(x);
    auto be = it, af = it;
    if (it != st.begin()) --be;
    if (af != --st.end()) ++af;
    //cout << *be << ' ' << x << ' ' << *af << '\n';
    if (af == it) --sum[x - *be], s -= x - *be, check(x - *be);
    else if (be == it) --sum[*af - x], s -= *af - x, check(*af - x);
    else --sum[x - *be], --sum[*af - x], ++sum[*af - *be], check(x - *be), check(*af - x);
    st.erase(it);
}

int main() {
    IOS; cin >> n >> m;
    rep (i, 1, n) cin >> k, insert(k);
    if (!sum.empty())cout << s - (*sum.rbegin()).fi << '\n';
    else cout << s << '\n';
    rep (i, 1, m) {
        cin >> _ >> k;
        if (_) insert(k);
        else delet(k);
        if (!sum.empty()) cout << s - (*sum.rbegin()).fi << '\n';
        else cout << s << '\n';
    }
    return 0;
}