Submission #959201

#	Time	Username	Problem	Language	Result	Execution time	Memory
959201		vjudge1	Dango Maker (JOI18_dango_maker)	C++17	13 / 100	1 ms	2652 KiB

dango_maker

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vll = vector <ll>;

const ll MAXN = 3E3+16;
char mat[MAXN][MAXN];
vector <pair <int, int> > th[2*MAXN];
ll dpBlue[MAXN];
ll dpRed[MAXN];
bool vBlue[MAXN];
bool vRed[MAXN];

int main () {
    cin.tie(nullptr) -> sync_with_stdio(false);
    ll n, m;
    cin >> n >> m;
    for (ll i = 0; i < n; i++) {
        for (ll j = 0; j < m; j++) {
            cin >> mat[i][j];
            if (mat[i][j] == 'R') mat[i][j] = '1';
            if (mat[i][j] == 'G') mat[i][j] = '2';
            if (mat[i][j] == 'W') mat[i][j] = '3';
            th[i+j].push_back({ i, j });
        }
    }
    auto isBlue = [&](ll i, ll j) {
        if (0 <= i && i < n)
        if (0 <= j && j+2 < m)
            return mat[i][j] == '1' && mat[i][j+1] == '2' && mat[i][j+2] == '3';
        return false;
    };
    auto isRed = [&](ll i, ll j) {
        if (0 <= i && i+2 < n)
        if (0 <= j && j < m)
            return mat[i][j] == '1' && mat[i+1][j] == '2' && mat[i+2][j] == '3';
        return false;
    };
    ll ans = 0;
    for (ll sum = 0; sum <= n+m; sum++) {
        if (!th[sum].size()) continue;
        int off = 1E9;
        for (auto [i, j] : th[sum]) off = min(off, j);
        ll sz = th[sum].size()+6;
        memset(dpBlue, 0, sizeof(ll)*sz);
        memset(dpRed, 0, sizeof(ll)*sz);
        memset(vBlue, 0, sizeof(bool)*sz);
        memset(vRed, 0, sizeof(bool)*sz);
        for (auto [i, j] : th[sum]) {
            if (isBlue(i, j)) vBlue[j-off+3] = true;
            if (isRed(i, j)) vRed[j-off+1] = true;
        }
        for (ll i = 1; i < sz; i++) {
            dpBlue[i] = dpBlue[i-1];
            dpRed[i] = dpRed[i-1];
            if (vBlue[i]) dpBlue[i] = max({ dpBlue[i-1], dpRed[i-3] })+1;
            if (vRed[i]) dpRed[i] = max({ dpRed[i-1], dpBlue[i-3] })+1;
        }
        ans += max(dpBlue[sz-1], dpRed[sz-1]);
    }
    cout << ans << '\n';
    return 0;
}

• Subtask 1: 13 / 13
• Subtask 2: 0 / 20
• Subtask 3: 0 / 67