Codeforces Round #792 (Div. 1 + Div. 2) C. Column Swapping
- Time : O(nmlogm)
- Space : O(nm)
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| #include <bits/stdc++.h>
#pragma optimization_level 3
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math,O3")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimization ("unroll-loops")
struct PairHash {inline std::size_t operator()(const std::pair<int,int> & v) const {return v.first*31+v.second;}};
#define MAX_N 50505
#define INF 987654321
#define EPS 1e-9
#define ll long long
#define pll pair<ll, ll>
#define vpll vector<pll>
#define vall3 vector<array<ll,3>>
#define all3 array<ll,3>
#define all5 array<ll,5>
#define vall5 vector<all5>
#define vll vector<ll>
#define vs vector<string>
#define usll unordered_set<ll>
#define uspll unordered_set<pll, PairHash>
#define vvs vector<vs>
#define vvll vector<vll>
#define all(a) begin(a), end(a)
using namespace std;
bool inc(vll& A) {
ll n = A.size();
for(ll i = 0; i < n - 1; i++) {
if(A[i] > A[i + 1]) return false;
}
return true;
}
vll solve(vvll& A) {
vvll sorted = A;
for(auto& s : sorted) sort(all(s));
vll bad;
ll n = A.size(), m = A[0].size();
for(ll i = 0; i < n and bad.size() < 2; i++) {
for(ll j = 0; j < m and bad.size() < 2; j++)
if(A[i][j] != sorted[i][j]) bad.push_back(j);
}
if(bad.empty()) return {1, 1};
if(bad.size() != 2) return {-1};
for(auto& a : A) {
swap(a[bad[0]], a[bad[1]]);
if(!inc(a)) return {-1};
}
return {bad[0] + 1, bad[1] + 1};
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
ll tc;
cin>>tc;
for(ll i = 1; i <= tc; i++) {
ll n, m;
cin>>n>>m;
vvll A(n, vll(m));
for(ll j = 0; j < n; j++)
for(ll k = 0; k < m; k++)
cin>>A[j][k];
auto res = solve(A);
for(auto& a : res) cout<<a<<' ';cout<<endl;
}
return 0;
}
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