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ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#665124 | #5543. The Only Mode | temmie | RE | 0ms | 0kb | C++17 | 2.7kb | 2024-10-22 04:23:06 | 2024-10-22 04:23:06 |
answer
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define ALL(x) x.begin(), x.end()
#define SZ(x) ((int)x.size())
#define fastio ios::sync_with_stdio(0), cin.tie(0);
using namespace std;
#ifdef LOCAL
#define cout cout << "\033[0;32m"
#define cerr cerr << "\033[0;31m"
#define endl "\n" << "\033[0m"
#else
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,avx2,sse,sse2,sse3,sse4,popcnt")
#define endl "\n"
#endif
const int MAX_N = 2e5+100;
const int INF = 2e9;
const int P = 1e5+10;
// declare
int n;
vector<int> v;
vector<int> d[4][4];
struct BinaryIndexTree{
vector<int> BIT;
vector<int> backup;
BinaryIndexTree(int n){
BIT.assign(n, INF);
return;
}
void update(int pos, int val){
pos += P;
backup.push_back(pos);
for (int i=pos ; i<SZ(BIT) ; i+=i&-i) BIT[i] = min(BIT[i], val);
}
int query(int pos){
pos += P;
int ret = INF;
for (int i=pos ; i ; i-=i&-i) ret = min(ret, BIT[i]);
return ret;
}
void reset(){
for (auto pos : backup) for (int i=pos ; i<SZ(BIT) ; i+=i&-i) BIT[i] = INF;
backup.clear();
}
};
/*
1. 先根據一維遞增排序
2. 在根據二維遞減排序
*/
void solve1(){
// init
for (int i=0 ; i<4 ; i++){
for (int j=0 ; j<4 ; j++){
d[i][j].resize(MAX_N);
}
}
// input
cin >> n;
v.resize(n);
for (int i=0 ; i<n ; i++) cin >> v[i];
// process
for (int i=0 ; i<n ; i++) for (int j=0 ; j<4 ; j++) for (int k=0 ; k<4 ; k++){
if (v[i]==j) d[j][k][i]++;
if (v[i]==k) d[j][k][i]--;
}
for (int i=1 ; i<n ; i++) for (int j=0 ; j<4 ; j++) for (int k=0 ; k<4 ; k++) d[j][k][i] += d[j][k][i-1];
// 解決三維偏序 [l, r)
BinaryIndexTree BIT(n*2+5);
auto CDQ = [&](auto self, int l, int r, vector<vector<int>> &v){
if (r-l<=1) return 0;
int mid = (l+r)/2;
int ans = max(self(self, l, mid, v), self(self, mid, r, v));
vector<vector<int>> tmp;
int i, j;
for (i=l, j=mid ; j<r ; j++){
while (i<mid && v[i][1]<v[j][1]){
BIT.update(v[i][2], v[i][3]);
tmp.push_back(v[i]);
i++;
}
ans = max(ans, v[j][3]-BIT.query(v[j][2]-1));
tmp.push_back(v[j]);
}
BIT.reset();
while (i<mid){
tmp.push_back(v[i]);
i++;
}
copy(ALL(tmp), v.begin()+l);
return ans;
};
for (int i=0 ; i<4 ; i++){
vector<vector<int>> v(n);
v.push_back({0, 0, 0, -1});
for (int j=0 ; j<n ; j++){
for (int k=0 ; k<4 ; k++){
if (i==k) continue;
v[j].push_back(d[i][k][j]);
}
v[j].push_back(j);
}
sort(v.begin(), v.end(), [](auto a, auto b){
if (a[0]==b[0]) return a[1]>b[1];
return a[0]<b[0];
});
int ans = CDQ(CDQ, 0, n+1, v);
cout << ans << " ";
}
cout << endl;
return;
}
signed main(){
fastio;
int t = 1;
while (t--){
solve1();
}
return 0;
}
详细
Test #1:
score: 0
Runtime Error
input:
7 1 2 2 0 3 0 3