# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
1214013 | aykhn | Genetics (BOI18_genetics) | C11 | 0 ms | 0 KiB |
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define inf 0x3F3F3F3F3F3F3F3F
const int MXN = 5e3 + 1;
const int mod = 1e9 + 7;
int val[MXN];
int mp[1000];
int id[MXN][4];
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
mp['A'] = 0, mp['C'] = 1, mp['G'] = 2, mp['T'] = 3;
int n, m, k;
cin >> n >> m >> k;
for (int i = 0; i < n; i++) val[i] = rng() % mod;
string s[n];
for (int i = 0; i < n; i++)
{
cin >> s[i];
for (int j = 0; j < m; j++)
{
int x = mp[s[i][j]];
id[j][x] = (id[j][x] + val[i]) % mod;
}
}
for (int i = 0; i < n; i++)
{
int need = 0, have = 0;
for (int j = 0; j < n; j++)
{
if (i != j) need = (need + val[j] * k % mod) % mod;
}
for (int j = 0; j < m; j++)
{
for (int x = 0; x < 4; x++)
{
if (x != mp[s[i][j]]) have = (have + id[j][x]) % mod;
}
}
if (have == need)
{
cout << i + 1 << '\n';
return 0;
}
}
assert(0);
}