Submission #711332

#	Time	Username	Problem	Language	Result	Execution time	Memory
711332		sysia	The short shank; Redemption (BOI21_prison)	C++17	100 / 100	1999 ms	98576 KiB

prison

//Sylwia Sapkowska
#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
using namespace std;

void __print(int x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ", "; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? ", " : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef LOCAL
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif

typedef pair<int, int> T;
const int oo = 1e9+7;

struct TreeMin{
    vector<T>tab;
    int size = 1;

    TreeMin(int n, vector<int>&a){
        while (size < n) size*=2;
        tab.assign(2*size, {oo, oo});
        for (int i = 1; i<(int)a.size(); i++) tab[i+size] = {a[i], i};
        for (int i = size-1; i>=1; i--) tab[i] = min(tab[2*i], tab[2*i+1]);
    }

    T query(int l, int r){
        T ans = {oo, oo};
        for (l += size-1, r += size+1; r-l>1; l/=2, r/=2){
            if (!(l&1)) ans = min(ans, tab[l+1]);
            if (r&1) ans = min(ans, tab[r-1]);
        }
        return ans;
    }

    void update(int x) {
        x += size;
        tab[x] = {oo, oo};
        while (x){
            x/=2;
            tab[x] = min(tab[2*x], tab[2*x+1]);
        }
    }
};

struct Tree{
    vector<int>tab, lazy;
    int size = 1;

    Tree(int n){
        while (size < n) size*=2;
        tab.assign(2*size, 0);
        lazy.assign(2*size, 0);
    }

    void update(int x, int lx, int rx, int l, int r, int v){
        if (lx != rx) push(x);
        if (lx > r || rx < l) return;
        if (lx >= l && rx <= r) {
            tab[x] += v;
            lazy[x] += v;
            return;
        }
        int m = (lx+rx)/2;
        update(2*x, lx, m, l, r, v);
        update(2*x+1, m+1, rx, l, r, v);
        tab[x] = max(tab[2*x], tab[2*x+1]);
    }

    void push(int x){
        if (!lazy[x]) return;
        tab[2*x] += lazy[x];
        tab[2*x+1] += lazy[x];
        lazy[2*x] += lazy[x];
        lazy[2*x+1] += lazy[x];
        lazy[x] = 0;
    }

    int find(int x, int lx, int rx){
        if (lx == rx) return lx;
        push(x);
        int m = (lx+rx)/2;
        if (tab[2*x] < tab[2*x+1]) return find(2*x+1, m+1, rx);
        return find(2*x, lx, m);
    }
};

void read(int &x){
    register int c;
    x = 0;
    c = getchar();
    for (; (c>47 && c<58); c=getchar()) x = x*10 + c - 48;
}

void solve(){
    int n, d, tt;read(n); read(d); read(tt);
    vector<int>prev(n+1, oo);
    stack<int>s;
    vector<int>t(n+1);
    for (int i = 1; i<=n; i++) read(t[i]);
    for (int i = 1; i<=n; i++){
        s.push(i);
        while ((int)s.size() && s.top() - t[s.top()] < i - tt) s.pop();
        if ((int)s.size()) prev[i] = s.top();   
    }
    debug(prev);
    TreeMin tmin(n+2, prev);
    Tree tans(n+1);
    for (int i = 1; i<=n; i++){
        if (prev[i] <= i){
            debug(prev[i], i);
            tans.update(1, 0, tans.size-1, prev[i], i, 1);
        }
    }
    while (d--){
        int x = tans.find(1, 0, tans.size-1);
        debug(x);
        bool any = 0;
        while (1){
            T now = tmin.query(x+1, n+1);
            if (now.first > x) break;
            debug(now);
            tans.update(1, 0, tans.size-1, now.first, now.second, -1);
            tmin.update(now.second);
            prev[now.second] = oo;
            any = 1;
        }
        if (!any) break;
    }
    int ans = 0;
    debug(prev);
    for (int i = 1; i<=n; i++) if (prev[i] != oo) ans++;
    cout << ans << "\n";
}

int32_t main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    solve();

    return 0;
}

Compilation message (stderr)

prison.cpp: In function 'void read(int&)':
prison.cpp:103:18: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
  103 |     register int c;
      |                  ^

• Subtask 1: 15 / 15
• Subtask 2: 10 / 10
• Subtask 3: 20 / 20
• Subtask 4: 10 / 10
• Subtask 5: 25 / 25
• Subtask 6: 20 / 20