Submission #545850

#	Time	Username	Problem	Language	Result	Execution time	Memory
545850		Monarchuwu	Land of the Rainbow Gold (APIO17_rainbow)	C++17	0 / 100	3061 ms	34168 KiB

rainbow

#include<iostream>
#include<algorithm>
#include<set>
#include<map>
using namespace std;
typedef long long ll;

typedef pair<int, int> pii;
#define ff first
#define ss second

const int N = 5e5 + 8;
const int dr[8] = { 0, 0, 1, -1, 1, 1, -1, -1 };
const int dc[8] = { 1, -1, 0, 0, 1, -1, 1, -1 };
int r, c, m, q, sr, sc;
int num[256];
string s;

namespace subtask1 {
    bool vis_init[52][52], vis[52][52];
    void init() {
        vis_init[sr][sc] = true;
        for (char c : s) {
            sr += dr[num[c]];
            sc += dc[num[c]];
            vis_init[sr][sc] = true;
        }
    }
    void dfs(int i, int j) {
        vis[i][j] = true;
        for (int k = 0, i2, j2; k < 4; ++k) {
            i2 = i + dr[k], j2 = j + dc[k];
            if (!vis[i2][j2]) dfs(i2, j2);
        }
    }
    int solve(int ar, int ac, int br, int bc) {
        int m = br - ar + 1, n = bc - ac + 1;
        for (int i = 1; i <= m; ++i) vis[i][0] = vis[i][n + 1] = true;
        for (int j = 1; j <= n; ++j) vis[0][j] = vis[m + 1][j] = true;
        for (int i = 1; i <= m; ++i)
            for (int j = 1; j <= n; ++j)
                vis[i][j] = vis_init[i + ar - 1][j + ac - 1];

        int cnt(0);
        for (int i = 1; i <= m; ++i)
            for (int j = 1; j <= n; ++j)
                if (!vis[i][j]) dfs(i, j), ++cnt;
        return cnt;
    }
}

namespace subtask2 {
    bool vis[4][N];
    int prf[4][N];
    void init() {
        vis[1][0] = vis[2][0] = vis[sr][sc] = true;
        for (char c : s) {
            sr += dr[num[c]];
            sc += dc[num[c]];
            vis[sr][sc] = true;
        }
        for (int i = 1; i <= c; ++i) {
            prf[1][i] = prf[1][i - 1] + (vis[1][i - 1] && !vis[1][i]);
            prf[2][i] = prf[2][i - 1] + (vis[2][i - 1] && !vis[2][i]);
            prf[3][i] = prf[3][i - 1] + (vis[1][i - 1] && vis[2][i - 1] && (!vis[1][i] || !vis[2][i]));
        }
    }
    int solve(int ar, int ac, int br, int bc) {
        if (ar == br) {
            return prf[ar][bc] - prf[ar][ac - 1] + (!vis[ar][ac - 1] && !vis[ar][ac]);
        }
        else {
            return prf[3][bc] - prf[3][ac - 1] + ((!vis[1][ac - 1] || !vis[2][ac - 1]) && (!vis[1][ac] || !vis[2][ac]));
        }
    }
}

namespace subtask3 {
    set<pii> vis, arr_set;
    map<pii, int> mp;
    pii a[N << 2];
    void init() {
        vis.emplace(sr, sc);
        for (char c : s) {
            sr += dr[num[c]];
            sc += dc[num[c]];
            vis.emplace(sr, sc);
        }

        arr_set = vis;
        for (pii x : arr_set) {
            for (int k = 0; k < 8; ++k) {
                pii p(x.ff + dr[k], x.ss + dc[k]);
                if (1 <= p.ff && p.ff <= r && 1 <= p.ss && p.ss <= c && vis.insert(p).ss)
                    a[mp[p] = mp.size() + 1] = p;
            }
        }
    }

    int par[N << 2];
    int root(int u) { return par[u] < 0 ? u : par[u] = root(par[u]); }
    bool Union(int u, int v) {
        if ((u = root(u)) == (v = root(v))) return false;
        if (par[u] > par[v]) swap(u, v);
        par[u] += par[v];
        par[v] = u;
        return true;
    }

    int solve(int ar, int ac, int br, int bc) {
        int cnt(0);
        for (int i = 1; i <= mp.size(); ++i)
            par[i] = ar <= a[i].ff && a[i].ff <= br && ac <= a[i].ss && a[i].ss <= bc ? (++cnt, -1) : 0;

        // inside or outside
        if (cnt == 0) {
            for (pii p : arr_set) {
                if (ar <= p.ff && p.ff <= br && ac <= p.ss && p.ss <= bc) return 0;
            }
            return 1;
        }

        for (int i = 1; i <= mp.size(); ++i) if (par[i]) {
            for (int k = 0; k < 4; ++k) {
                pii p = a[i];
                p.ff += dr[k];
                p.ss += dc[k];
                if (mp.count(p)) {
                    int j = mp[p];
                    if (par[j]) cnt -= Union(i, j);
                }
            }
        }
        return cnt;
    }
}

void init(int R, int C, int SR, int SC, int M, char *S) {
    num['E'] = 0, num['W'] = 1, num['S'] = 2, num['N'] = 3;
    r = R, c = C, sr = SR, sc = SC, m = M;
    for (int i = 0; i < m; ++i) s.push_back(S[i]);

    subtask3::init();
    return;

    if (r <= 50 && c <= 50)
        subtask1::init();
    else if (r == 2)
        subtask2::init();
    else
        subtask3::init();
}

int colour(int ar, int ac, int br, int bc) {
    return subtask3::solve(ar, ac, br, bc);

    if (r <= 50 && c <= 50)
        return subtask1::solve(ar, ac, br, bc);
    else if (r == 2)
        return subtask2::solve(ar, ac, br, bc);
    else
        return subtask3::solve(ar, ac, br, bc);
}

Compilation message (stderr)

rainbow.cpp: In function 'void subtask1::init()':
rainbow.cpp:24:26: warning: array subscript has type 'char' [-Wchar-subscripts]
   24 |             sr += dr[num[c]];
      |                          ^
rainbow.cpp:25:26: warning: array subscript has type 'char' [-Wchar-subscripts]
   25 |             sc += dc[num[c]];
      |                          ^
rainbow.cpp: In function 'void subtask2::init()':
rainbow.cpp:58:26: warning: array subscript has type 'char' [-Wchar-subscripts]
   58 |             sr += dr[num[c]];
      |                          ^
rainbow.cpp:59:26: warning: array subscript has type 'char' [-Wchar-subscripts]
   59 |             sc += dc[num[c]];
      |                          ^
rainbow.cpp: In function 'void subtask3::init()':
rainbow.cpp:85:26: warning: array subscript has type 'char' [-Wchar-subscripts]
   85 |             sr += dr[num[c]];
      |                          ^
rainbow.cpp:86:26: warning: array subscript has type 'char' [-Wchar-subscripts]
   86 |             sc += dc[num[c]];
      |                          ^
rainbow.cpp: In function 'int subtask3::solve(int, int, int, int)':
rainbow.cpp:112:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::map<std::pair<int, int>, int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  112 |         for (int i = 1; i <= mp.size(); ++i)
      |                         ~~^~~~~~~~~~~~
rainbow.cpp:123:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::map<std::pair<int, int>, int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  123 |         for (int i = 1; i <= mp.size(); ++i) if (par[i]) {
      |                         ~~^~~~~~~~~~~~

• Subtask 1: 0 / 11
• Subtask 2: 0 / 12
• Subtask 3: 0 / 24
• Subtask 4: 0 / 27
• Subtask 5: 0 / 26