結果
| 問題 |
No.1371 交換門松列・松
|
| コンテスト | |
| ユーザー |
 沙耶花
|
| 提出日時 | 2021-01-29 22:13:21 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 107 ms / 4,000 ms |
| コード長 | 5,781 bytes |
| コンパイル時間 | 2,122 ms |
| コンパイル使用メモリ | 206,072 KB |
| 最終ジャッジ日時 | 2025-01-18 09:18:05 |
|
ジャッジサーバーID （参考情報） |
judge4 / judge1 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 29 |
コンパイルメッセージ
main.cpp: In function ‘int main()’:
main.cpp:163:22: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
163 | scanf("%d",&A[i]);
| ~~~~~^~~~~~~~~~~~
ソースコード
#include <stdio.h>
#include <bits/stdc++.h>
#include <cassert>
#include <numeric>
#include <type_traits>
namespace atcoder {
namespace internal {
#ifndef _MSC_VER
template <class T>
using is_signed_int128 =
typename std::conditional<std::is_same<T, __int128_t>::value ||
std::is_same<T, __int128>::value,
std::true_type,
std::false_type>::type;
template <class T>
using is_unsigned_int128 =
typename std::conditional<std::is_same<T, __uint128_t>::value ||
std::is_same<T, unsigned __int128>::value,
std::true_type,
std::false_type>::type;
template <class T>
using make_unsigned_int128 =
typename std::conditional<std::is_same<T, __int128_t>::value,
__uint128_t,
unsigned __int128>;
template <class T>
using is_integral = typename std::conditional<std::is_integral<T>::value ||
is_signed_int128<T>::value ||
is_unsigned_int128<T>::value,
std::true_type,
std::false_type>::type;
template <class T>
using is_signed_int = typename std::conditional<(is_integral<T>::value &&
std::is_signed<T>::value) ||
is_signed_int128<T>::value,
std::true_type,
std::false_type>::type;
template <class T>
using is_unsigned_int =
typename std::conditional<(is_integral<T>::value &&
std::is_unsigned<T>::value) ||
is_unsigned_int128<T>::value,
std::true_type,
std::false_type>::type;
template <class T>
using to_unsigned = typename std::conditional<
is_signed_int128<T>::value,
make_unsigned_int128<T>,
typename std::conditional<std::is_signed<T>::value,
std::make_unsigned<T>,
std::common_type<T>>::type>::type;
#else
template <class T> using is_integral = typename std::is_integral<T>;
template <class T>
using is_signed_int =
typename std::conditional<is_integral<T>::value && std::is_signed<T>::value,
std::true_type,
std::false_type>::type;
template <class T>
using is_unsigned_int =
typename std::conditional<is_integral<T>::value &&
std::is_unsigned<T>::value,
std::true_type,
std::false_type>::type;
template <class T>
using to_unsigned = typename std::conditional<is_signed_int<T>::value,
std::make_unsigned<T>,
std::common_type<T>>::type;
#endif
template <class T>
using is_signed_int_t = std::enable_if_t<is_signed_int<T>::value>;
template <class T>
using is_unsigned_int_t = std::enable_if_t<is_unsigned_int<T>::value>;
template <class T> using to_unsigned_t = typename to_unsigned<T>::type;
} // namespace internal
} // namespace atcoder
#include <cassert>
#include <vector>
namespace atcoder {
// Reference: https://en.wikipedia.org/wiki/Fenwick_tree
template <class T> struct fenwick_tree {
using U = internal::to_unsigned_t<T>;
public:
fenwick_tree() : _n(0) {}
fenwick_tree(int n) : _n(n), data(n) {}
void add(int p, T x) {
assert(0 <= p && p < _n);
p++;
while (p <= _n) {
data[p - 1] += U(x);
p += p & -p;
}
}
T sum(int l, int r) {
assert(0 <= l && l <= r && r <= _n);
return sum(r) - sum(l);
}
private:
int _n;
std::vector<U> data;
U sum(int r) {
U s = 0;
while (r > 0) {
s += data[r - 1];
r -= r & -r;
}
return s;
}
};
} // namespace atcoder
using namespace atcoder;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000000
bool is_kadomatsu(long long a,long long b,long long c){
if(a==b||b==c||c==a)return false;
if(b>a&&b>c)return true;
if(b<a&&b<c)return true;
return false;
}
int main(){
int N;
cin>>N;
vector<int> A(N);
vector<int> ind(N);
rep(i,N){
scanf("%d",&A[i]);
A[i]--;
ind[i] = i;
}
sort(ind.begin(),ind.end(),[&](int a,int b){
return A[a]<A[b];
});
vector<bool> larger(N,false);
rep(i,N){
if(i==0){
if(A[1]<A[0])larger[i] = true;
}
else{
if(!larger[i-1])larger[i] = true;
}
}
fenwick_tree<long long> F(N);
vector<vector<int>> Del(N+1),Add(N+1);
rep(i,N){
if(larger[i]){
int m = 0;
if(i!=0)m = max(m,A[i-1]);
if(i!=N-1)m = max(m,A[i+1]);
m++;
Add[m].push_back(i);
}
else{
int m = Inf;
if(i!=0)m = min(m,A[i-1]);
if(i!=N-1)m = min(m,A[i+1]);
Del[m].push_back(i);
F.add(A[i],1);
}
}
long long ans = 0LL;
rep(i,N){
int t = A[ind[i]];
rep(j,Del[t].size()){
F.add(A[Del[t][j]],-1);
}
Del[t].clear();
rep(j,Add[t].size()){
F.add(A[Add[t][j]],1);
}
Add[t].clear();
int ii = ind[i];
if(larger[ii]){
int m = 0;
if(ii!=0)m = max(m,A[ii-1]);
if(ii!=N-1)m = max(m,A[ii+1]);
m++;
ans += F.sum(m,N);
}
else{
int m = Inf;
if(ii!=0)m = min(m,A[ii-1]);
if(ii!=N-1)m = min(m,A[ii+1]);
ans += F.sum(0,m);
}
}
ans -= N;
ans /= 2;
cout<<ans<<endl;
return 0;
}