Submission #367363

#	Time	Username	Problem	Language	Result	Execution time	Memory
367363		lookcook	Growing Vegetable is Fun 3 (JOI19_ho_t3)	C++17	0 / 100	1090 ms	56300 KiB

joi2019_ho_t3

#include <bits/stdc++.h>

#define int long long

using namespace std;

int dp[3][70][70][70][70]; // 0 = r, 1 = g, 2 = y
int n;
vector<int> r, g, y;
string s;
int nxt[3][70][70][70][70];

int rec(int pos, int rp, int gp, int yp, int lst) {
    if (pos == n) return 0;
    if (dp[lst][pos][rp][gp][yp] != -1) return dp[lst][pos][rp][gp][yp];
    int res = 1e15;
    if (!r.empty() && r.size()!=rp && lst!=0) {
        int val = rec(pos+1, rp+1, gp, yp, 0) + abs(r[rp]-pos);
        if (val < res) {
            res = val;
            nxt[lst][pos][rp][gp][yp] = 0;
        }
    }
    if (!g.empty() && g.size()!=gp && lst!=1) {
        int val = rec(pos+1, rp, gp+1, yp, 1) + abs(g[gp]-pos);
        if (val < res) {
            res = val;
            nxt[lst][pos][rp][gp][yp] = 1;
        }
    }
    if (!y.empty() && y.size()!=yp && lst!=2) {
        int val = rec(pos+1, rp, gp, yp+1, 2) + abs(y[yp]-pos);
        if (val < res) {
            res = val;
            nxt[lst][pos][rp][gp][yp] = 2;
        }
    }
    dp[lst][pos][rp][gp][yp] = res;
    return res;
}

int fast() {
    r = {}, g = {}, y = {};
    for (int i = 0; i < 3; i++)
        for (int a = 0; a <= n; a++)
            for (int b = 0; b <= n; b++)
                for (int c = 0; c <= n; c++)
                    for (int d = 0; d <= n; d++)
                        dp[i][a][b][c][d] = -1;
    for (int i = 0; i < n; i++) {
        if (s[i] == 'R') r.push_back(i);
        if (s[i] == 'G') g.push_back(i);
        if (s[i] == 'Y') y.push_back(i);
    }
    int res = min(rec(0,0,0,0,1),rec(0,0,0,0,0));
    if (res >= 1e15) return -1;
    else return res/2;
}

int slow() {
    queue<pair<string,int>> q;
    q.push({s,0});
    set<string> vis;
    vis.insert(s);
    while (!q.empty()) {
        pair<string,int> p = q.front();
        q.pop();
        bool ok = true;
        for (int i = 1; i < s.length(); i++) {
            if (p.first[i] == p.first[i-1]) {
                ok = false;
            }
        }
        if (ok) {
            cout << "End state: " << p.first << " dist = " << p.second << '\n';
            return p.second;
        }
        for (int i = 1; i < p.first.length(); i++) {
            string t = p.first;
            swap(t[i],t[i-1]);
            if (vis.count(t) == 0) {
                vis.insert(t);
                q.push({t,p.second+1});
            }
        }
    }
    return -1;
}

char a[8];
void gen(int x) {
    if (x == n) {
        s = "";
        for (int i = 0; i < n; i++) s += a[i];
        int fa = fast();
        int sl = slow();
        if (fa != sl) {
            cout << "WA, fast=" << fa << " slow=" << sl << '\n';
            cout << s << '\n';
            exit(0);
        }
        return;
    }
    a[x] = 'R';
    gen(x+1);
    a[x] = 'G';
    gen(x+1);
    a[x] = 'Y';
    gen(x+1);
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    //n = 9;
    //gen(0);
    cin >> n >> s;
    fast();
    int pos = 0, rp = 0, gp = 0, yp = 0, lst = 1;
    string str = "";
    while (pos != n) {
        int to = nxt[lst][pos][rp][gp][yp];
        if (to == 0) {
            str += 'R';
            rp++;
        }
        if (to == 1) {
            str += 'G';
            gp++;
        }
        if (to == 2) {
            str += 'Y';
            yp++;
        }
        lst = to;
        pos++;
    }
    //cout << "dp end state = " << str << '\n';
    int swaps = 0;
    for (int i = 0; i < str.length(); i++) {
        if (s[i] != str[i]) {
            int p = -1;
            for (int j = i+1; j < str.length(); j++) {
                if (s[j] == str[i]) {
                    p = j;
                    break;
                }
            }
            for (int j = p; j >= i+1; j--) {
                swap(s[j],s[j-1]);
                swaps++;
            }
        }
    }
    cout << swaps << '\n';
}

Compilation message (stderr)

joi2019_ho_t3.cpp: In function 'long long int rec(long long int, long long int, long long int, long long int, long long int)':
joi2019_ho_t3.cpp:17:31: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
   17 |     if (!r.empty() && r.size()!=rp && lst!=0) {
      |                       ~~~~~~~~^~~~
joi2019_ho_t3.cpp:24:31: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
   24 |     if (!g.empty() && g.size()!=gp && lst!=1) {
      |                       ~~~~~~~~^~~~
joi2019_ho_t3.cpp:31:31: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
   31 |     if (!y.empty() && y.size()!=yp && lst!=2) {
      |                       ~~~~~~~~^~~~
joi2019_ho_t3.cpp: In function 'long long int slow()':
joi2019_ho_t3.cpp:69:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   69 |         for (int i = 1; i < s.length(); i++) {
      |                         ~~^~~~~~~~~~~~
joi2019_ho_t3.cpp:78:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   78 |         for (int i = 1; i < p.first.length(); i++) {
      |                         ~~^~~~~~~~~~~~~~~~~~
joi2019_ho_t3.cpp: In function 'int main()':
joi2019_ho_t3.cpp:140:23: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  140 |     for (int i = 0; i < str.length(); i++) {
      |                     ~~^~~~~~~~~~~~~~
joi2019_ho_t3.cpp:143:33: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  143 |             for (int j = i+1; j < str.length(); j++) {
      |                               ~~^~~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 55
• Subtask 3: 0 / 15
• Subtask 4: 0 / 25