# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
1221514 | nibert | Message (IOI24_message) | C++20 | 0 ms | 0 KiB |
#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
using namespace std;
vector<int> ucs(vector<int> A, vector<int> B) {
int N = A.size(), M = B.size();
vector<vector<int>> dp(N + 1, vector<int>(M + 1, 0));
for (int i = N - 1; i >= 0; --i) {
for (int j = M - 1; j >= 0; --j) {
if (A[i] == B[j]) {
dp[i][j] = 1 + dp[i + 1][j + 1];
} else {
dp[i][j] = max(dp[i + 1][j], dp[i][j + 1]);
}
}
}
vector<int> lcs;
int i = 0, j = 0;
bool multiple = false;
while (i < N && j < M) {
if (A[i] == B[j]) {
lcs.push_back(A[i]);
i++;
j++;
} else if (dp[i + 1][j] == dp[i][j] && dp[i][j + 1] == dp[i][j]) {
multiple = true;
break;
} else if (dp[i + 1][j] == dp[i][j]) {
i++;
} else {
j++;
}
}
if (multiple) return {-1};
return lcs;
}