/*
doing virtual contest
start: 10:00
finish: 14:00
*/
#include <bits/stdc++.h>
using namespace std;
#ifndef EVAL
const int N_ = 5007;
int n_;
int a_[N_], ans_[N_];
int query(int s, int t) {
int mn = n_, mx = 1;
for (int i = s; i <= t; ++i) {
mn = min(mn, a_[i]);
mx = max(mx, a_[i]);
}
return mx - mn;
}
void answer(int i, int a) {
if (i < 1 || i > n_) {
cout << "incorrect index " << i << endl;
exit(0);
}
if (ans_[i] != -1) {
cout << i << " used twice" << endl;
exit(0);
}
ans_[i] = a;
}
void check_ans() {
bool corr = 1;
for (int i = 1; i <= n_; ++i) corr &= a_[i] == ans_[i];
if (!corr) {
cout << "incorrect" << endl;
for (int i = 1; i <= n_; ++i) cout << a_[i] << " ";
cout << endl;
for (int i = 1; i <= n_; ++i) cout << ans_[i] << " ";
cout << endl;
} else {
cout << "correct\n";
}
}
void init(int n, vector<int> a) {
n_ = n;
for (int i = 1; i <= n; ++i) {
a_[i] = a[i - 1];
ans_[i] = -1;
}
}
#endif
void solve(int n) {
int l = 1, r = n;
while (r - l > 1) {
int mid = (l + r) / 2;
if (query(1, mid) == n - 1) {
r = mid;
} else {
l = mid;
}
}
int posn = r;
l = 1, r = n;
while (r - l > 1) {
int mid = (l + r) / 2;
if (query(mid, n) == n - 1) {
l = mid;
} else {
r = mid;
}
}
int pos1 = l;
vector<int> a(n + 1, -1);
a[pos1] = 1;
a[posn] = n;
if (pos1 + 1 < n) a[pos1 + 1] = 1 + query(pos1, pos1 + 1);
for (int i = pos1 - 1; i > 0; --i) {
int x = a[i + 2], y = a[i + 1];
int d = query(i, i + 1);
if (abs(x - y) + d == query(i, i + 2)) {
a[i] = y < x ? y - d : y + d;
} else {
a[i] = y < x ? y + d : y - d;
}
}
for (int i = pos1 + 2; i < posn; ++i) {
int x = a[i - 2], y = a[i - 1];
int d = query(i - 1, i);
if (abs(x - y) + d == query(i - 2, i)) {
a[i] = y < x ? y - d : y + d;
} else {
a[i] = y < x ? y + d : y - d;
}
}
for (int i = posn + 1; i <= n; ++i) {
int x = a[i - 2], y = a[i - 1];
int d = query(i - 1, i);
if (abs(x - y) + d == query(i - 2, i)) {
a[i] = y < x ? y - d : y + d;
} else {
a[i] = y < x ? y + d : y - d;
}
}
for (int i = 1; i <= n; ++i) answer(i, a[i]);
}
#ifndef EVAL
int main() {
freopen("input.txt", "r", stdin);
ios::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
vector<int> a(n);
for (int i = 0; i < n; ++i) cin >> a[i];
init(n, a);
solve(n);
check_ans();
return 0;
}
#endif
Compilation message
xylophone.cpp: In function 'void solve(int)':
xylophone.cpp:64:13: error: 'query' was not declared in this scope
64 | if (query(1, mid) == n - 1) {
| ^~~~~
xylophone.cpp:74:13: error: 'query' was not declared in this scope
74 | if (query(mid, n) == n - 1) {
| ^~~~~
xylophone.cpp:84:41: error: 'query' was not declared in this scope
84 | if (pos1 + 1 < n) a[pos1 + 1] = 1 + query(pos1, pos1 + 1);
| ^~~~~
xylophone.cpp:87:17: error: 'query' was not declared in this scope
87 | int d = query(i, i + 1);
| ^~~~~
xylophone.cpp:96:17: error: 'query' was not declared in this scope
96 | int d = query(i - 1, i);
| ^~~~~
xylophone.cpp:105:17: error: 'query' was not declared in this scope
105 | int d = query(i - 1, i);
| ^~~~~
xylophone.cpp:112:34: error: 'answer' was not declared in this scope
112 | for (int i = 1; i <= n; ++i) answer(i, a[i]);
| ^~~~~~
