Hello, I was trying to solve UVa 103 using O(N²) Longest Increasing Subsequence. Here is my code:

#include <bits/stdc++.h>
using namespace std;

int K, N, dp[31];
pair<vector<int>, int> A[31];
string hist[31];

bool canFit(int i, int j) {
    for (int k = 0; k < N; ++k)
        if (A[i].first[k] >= A[j].first[k])
            return false;
    return true;
}

int main() {
    while (cin >> K >> N) {
        for (int i = 0; i < K; ++i) {
            A[i].first.resize(N, 0);
            for (int j = 0; j < N; ++j)
                cin >> A[i].first[j];
            A[i].second = i;
            sort(A[i].first.begin(), A[i].first.end());
        }
        sort(A, A+K);
        fill_n(dp, 31, 1);
        for (int i = 0; i < K; ++i)
            hist[i] = to_string(A[i].second+1);
        int ans = 1;
        string best = "1";
        for (int i = 1; i < K; ++i)
            for (int j = 0; j < i; ++j)
                if (canFit(j, i) && dp[j]+1 > dp[i]) {
                    dp[i] = dp[j]+1;
                    hist[i] = hist[j] + ' ' + to_string(A[i].second+1);
                    if (dp[i] > ans) {
                        ans = dp[i];
                        best = hist[i];
                    }
                }
        cout << ans << '\n' << best << '\n';
    }
	return 0;
}

I got WA with this submission. However, if I change one small detail, the code gets AC:

                    hist[i] = hist[j] + ' ' + to_string(A[i].second+1);
                    // Make this >= instead of >
                    // i.e. I save a maximum length path even if I already have one
                    if (dp[i] >= ans) {
                        ans = dp[i];
                        best = hist[i];
                    }

Why is this? I thought that using the strict > was okay, since the problem says that "If there is more than one longest nesting string then any one of them can be output." Is there something I'm missing? Thanks.

This year's Canadian Computing Competition was supposed to happen today, but it looks like it's being DDoS'd, and people can't submit to the judge. I've talked from some friends who were supposed to write today, and they said that UWaterloo has cancelled the competition. Can anyone confirm?