Submission #293524

#	Time	Username	Problem	Language	Result	Execution time	Memory
293524		crossing0ver	Exercise Deadlines (CCO20_day1problem2)	C++17	25 / 25	235 ms	8340 KiB

Main

#include<bits/stdc++.h>
#define vi vector<int>
#define pii pair<int,int>
#define fi first
#define se second
#define pb push_back
using namespace std;
const int N = 2e5+5;
int MX[4*N],sum[4*N];
vector<int> v,v1;
void build(int v,int tl,int tr) {
    if (tl == tr) {
        MX[v] = v1[tl];
        sum[v] = 1;
        return;
    }
    int tm = (tl + tr)/2;
    build(v*2,tl,tm);
    build(v*2+1,tm+1,tr);
    sum[v] = sum[v*2] + sum[v*2+1];
    MX[v] = max(MX[v*2],MX[v*2+1]);
}

long long  ans;
int idx;
void upd(int v,int tl,int tr,int val) {
    if (tl == tr) {
        sum[v] = 0;
        MX[v] = -1;
        idx = tl;
        return;
    }
    int tm = (tl + tr)/2;
    if (MX[v*2+1] >= val) {
        upd(v*2+1,tm+1,tr,val);
    }else
        upd(v*2,tl,tm,val);
    sum[v] = sum[v*2] + sum[v*2+1];
    MX[v] = max(MX[v*2],MX[v*2+1]);
}
int get(int v,int tl,int tr,int pos) {
    if (pos > tr) return 0;
    if (pos <= tl) return sum[v];
    int tm = (tl + tr)/2;
    return get(v*2,tl,tm,pos) +
        get(v*2+1,tm+1,tr,pos);

}
main() {
    int n;
    cin >> n;
    v.resize(n);
    for (int i = 0; i < n; i++) {
        cin >> v[i];
        --v[i];
    }
    vi g = v;
    v1 = v;
    sort(g.begin(),g.end());

    // INVALID
    for (int i = 0; i < n; i++)
    if (g[i] < i) {
        cout <<-1;
        return 0;
    }//
    build(1,0,n-1);

    for (int i = n-1; i >= 0; i--) {
        upd(1,0,n-1,i);
        ans += get(1,0,n-1,idx);


    }
    cout << ans;
    return 0;
}

Compilation message (stderr)

Main.cpp:49:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   49 | main() {
      |      ^

• Subtask 1: 17 / 17
• Subtask 2: 8 / 8