Submission #1092792

#	Time	Username	Problem	Language	Result	Execution time	Memory
1092792		Sunbae	Mountains (NOI20_mountains)	C++17	100 / 100	427 ms	29440 KiB

Mountains

#include <bits/stdc++.h> 
#include <ext/pb_ds/assoc_container.hpp> 
#include <ext/pb_ds/tree_policy.hpp>
typedef long long ll;
using namespace std;
using namespace __gnu_pbds;  
#define os tree<pair<ll,int>, null_type, less<pair<ll,int>>, rb_tree_tag,tree_order_statistics_node_update>
const int N = 3e5 + 5;
ll A[N], a[N], tot;
signed main(){
    int n; scanf("%d", &n);
    os s;
    for(int i = 0; i<n; ++i){
        scanf("%lld", a+i);
        A[i] = s.order_of_key(make_pair(a[i], -1));
        s.insert(make_pair(a[i], i));
    }
    s.clear();
    for(int i = n-1; i>=0; --i){
        tot += A[i] *= s.order_of_key(make_pair(a[i], -1));
        s.insert(make_pair(a[i], i));
    }
    printf("%lld", tot);
}

Compilation message (stderr)

Mountains.cpp: In function 'int main()':
Mountains.cpp:11:17: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |     int n; scanf("%d", &n);
      |            ~~~~~^~~~~~~~~~
Mountains.cpp:14:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |         scanf("%lld", a+i);
      |         ~~~~~^~~~~~~~~~~~~

• Subtask 1: 2 / 2
• Subtask 2: 4 / 4
• Subtask 3: 9 / 9
• Subtask 4: 36 / 36
• Subtask 5: 28 / 28
• Subtask 6: 9 / 9
• Subtask 7: 12 / 12