Submission #8530445

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Source Code Expand

#include <bits/stdc++.h>
#define REP(i, n) for (int i = 0; (i) < (int)(n); ++ (i))
#define REP_R(i, n) for (int i = (int)(n) - 1; (i) >= 0; -- (i))
using namespace std;
template <class T, class U> inline void chmin(T & a, U const & b) { a = min<T>(a, b); }

bool solve(int n, int m, int q, const vector<int> & a) {
    // make the final sequence
    vector<int> used(m);
    vector<int> b;
    REP_R (i, q) {
        if (not used[a[i]]) {
            used[a[i]] = true;
            b.push_back(a[i]);
        }
    }
    REP (i, m) {
        if (not used[i]) {
            b.push_back(i);
        }
    }

    // remove the tail
    int r = m - 1;
    while (r - 1 >= 0 and b[r - 1] < b[r]) {
        -- r;
    }
    if (r == 0) return true;

    // count queries
    vector<int> next(m, m);
    REP (i, r) {
        next[b[i]] = (i + 1 < r ? b[i + 1] : m);
    }
    vector<int> cnt(m + 1);
    cnt[b[0]] = n;
    REP_R (i, q) {
        if (cnt[a[i]]) {
            -- cnt[a[i]];
            ++ cnt[next[a[i]]];
        }
    }
    return cnt[m] == n;
}

int main() {
    int n, m; cin >> n >> m;
    int q; cin >> q;
    vector<int> a(q);
    REP (i, q) {
        cin >> a[i];
        -- a[i];
    }
    cout << (solve(n, m, q, a) ? "Yes" : "No") << endl;
    return 0;
}

Submission Info

Judge Result