Submission #575105

#	Time	Username	Problem	Language	Result	Execution time	Memory
575105		teki	Growing Vegetable is Fun 3 (JOI19_ho_t3)	C++11	100 / 100	459 ms	757608 KiB

joi2019_ho_t3

#include <bits/stdc++.h>

typedef long long ll;

#define pb push_back
#define MS(x,y) memset((x),(y),sizeof((x)))
#define MN 1000000007

using namespace std;

const int MAXN = 401;
vector<int> pos[3];
string org;
int pref[3][MAXN];
int n;
int dp[3][MAXN][MAXN][MAXN];

int convI(char c) {
    if (c == 'R') return 0;
    else if (c == 'G') return 1;
    else if (c == 'Y') return 2;
}

char convC(int b) {
    if (b == 0) return 'R';
    else if (b == 1) return 'G';
    else if (b == 2) return 'Y';
}

int kolkuPrefLast(int cnt, int koj) {
    if (cnt == -1) return 0;
    else return pref[koj][pos[koj][cnt]];
}

int rec(int last, int cntR, int cntG, int cntY) {
    if (cntR+cntG+cntY == n) return 0;
    if (dp[last][cntR][cntG][cntY] != -1) return dp[last][cntR][cntG][cntY];

    int ret = INT_MAX/2;
    int tmp[3] = {cntR,cntG,cntY};

    for (int i = 0; i<3; i++) {
        if (last == i && cntR+cntG+cntY != 0) continue;
        if (tmp[i] >= pos[i].size()) continue;
        int ctr = 0;

        for (int j = 0; j<3; j++) {
            if (i == j) continue;
            ctr += abs(pref[j][pos[i][tmp[i]]] - kolkuPrefLast(tmp[j]-1,j));
        }

        if (i == 0) ctr += rec(0,cntR+1,cntG,cntY);
        else if (i == 1) ctr += rec(1,cntR,cntG+1,cntY);
        else if (i == 2) ctr += rec(2,cntR,cntG,cntY+1);

        ret = min(ret,ctr);
    }


    return dp[last][cntR][cntG][cntY] = ret;
}

int main()
{
    #if LOCAL_DEBUG
        fstream cin("in.txt");
    #endif

    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    MS(dp,-1);
    MS(pref,0);

    cin>>n;
    cin>>org;

    for (int i = 0; i<n; i++) {
        for (int j = 0; j<3; j++) {
            if (i != 0) pref[j][i] = pref[j][i-1];

            if (org[i] == convC(j)) {
                pref[j][i]++;
                pos[j].pb(i);
            }
        }
    }

    int res = rec(0,0,0,0);

    if (res == INT_MAX/2) cout<<-1<<endl;
    else cout<<res/2<<endl;

    return 0;
}

Compilation message (stderr)

joi2019_ho_t3.cpp: In function 'int rec(int, int, int, int)':
joi2019_ho_t3.cpp:44:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |         if (tmp[i] >= pos[i].size()) continue;
      |             ~~~~~~~^~~~~~~~~~~~~~~~
joi2019_ho_t3.cpp: In function 'int convI(char)':
joi2019_ho_t3.cpp:22:1: warning: control reaches end of non-void function [-Wreturn-type]
   22 | }
      | ^
joi2019_ho_t3.cpp: In function 'char convC(int)':
joi2019_ho_t3.cpp:28:1: warning: control reaches end of non-void function [-Wreturn-type]
   28 | }
      | ^

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