[Problem link](https://mirror.codeforces.com/contest/1375/problem/E)<br>↵
↵
<spoiler summary="Tourist Code">↵
~~~~~↵
/**↵
* author: tourist↵
* created: 04.07.2020 18:34:48 ↵
**/↵
#include <bits/stdc++.h>↵
↵
using namespace std;↵
↵
int main() {↵
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];↵
}↵
vector<int> b(n);↵
iota(b.begin(), b.end(), 0);↵
sort(b.begin(), b.end(), [&](int i, int j) {↵
if (a[i] != a[j]) {↵
return a[i] < a[j];↵
}↵
return i < j;↵
});↵
vector<pair<int, int>> ret;↵
for (int it = 0; it < n; it++) {↵
for (int i = 0; i < n - 1; i++) {↵
if (b[i] > b[i + 1]) {↵
ret.emplace_back(b[i + 1], b[i]);↵
swap(b[i], b[i + 1]);↵
}↵
}↵
}↵
cout << ret.size() << '\n';↵
for (auto& p : ret) {↵
cout << p.first + 1 << " " << p.second + 1 << '\n';↵
}↵
return 0;↵
}↵
↵
~~~~~↵
</spoiler>↵
↵
What I do not understand is how after finding array b we get the correct answer.<br>↵
Thanks in advance.↵
↵
<spoiler summary="Tourist Code">↵
~~~~~↵
/**↵
* author: tourist↵
* created: 04.07.2020 18:34:48 ↵
**/↵
#include <bits/stdc++.h>↵
↵
using namespace std;↵
↵
int main() {↵
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];↵
}↵
vector<int> b(n);↵
iota(b.begin(), b.end(), 0);↵
sort(b.begin(), b.end(), [&](int i, int j) {↵
if (a[i] != a[j]) {↵
return a[i] < a[j];↵
}↵
return i < j;↵
});↵
vector<pair<int, int>> ret;↵
for (int it = 0; it < n; it++) {↵
for (int i = 0; i < n - 1; i++) {↵
if (b[i] > b[i + 1]) {↵
ret.emplace_back(b[i + 1], b[i]);↵
swap(b[i], b[i + 1]);↵
}↵
}↵
}↵
cout << ret.size() << '\n';↵
for (auto& p : ret) {↵
cout << p.first + 1 << " " << p.second + 1 << '\n';↵
}↵
return 0;↵
}↵
↵
~~~~~↵
</spoiler>↵
↵
What I do not understand is how after finding array b we get the correct answer.<br>↵
Thanks in advance.↵
