Submission #901675

#	Time	Username	Problem	Language	Result	Execution time	Memory
901675		jay_jayjay	Growing Vegetable is Fun 3 (JOI19_ho_t3)	C++14	100 / 100	283 ms	134760 KiB

joi2019_ho_t3

#include <bits/stdc++.h>
using namespace std;
#define all(x) x.begin(),x.end()

#define infl 0x3f3f3f3f3f3f3f3f
#define ll long long
template<typename T> void chmin(T& x, T y) { x=min(x,y); }

#define N 400

int n;
char s[N+1];
int pos[3][N+1];
int cnt[3][N+1][3];

int main()
{
        scanf("%d %s",&n,s);
        for(auto&x:s) x = x=='R'?0:x=='G'?1:x=='Y'?2:-1;

        int c[3]={0,0,0};
        for(int i=0;i<n;i++) {
                pos[s[i]][c[s[i]]]=i;
                for(int k=0;k<3;k++)
                        cnt[s[i]][c[s[i]]][k]=c[k];
                c[s[i]]++;
        }

        vector<vector<vector<vector<ll>>>> dp(c[0]+1,vector<vector<vector<ll>>>(c[1]+1,vector<vector<ll>>(c[2]+1,vector<ll>(3,infl))));

        //memset(dp,0x3f,sizeof(dp));
        for(int k=0;k<3;k++) dp[0][0][0][k]=0;
        for(int i0=0;i0<=c[0];i0++)
                for(int i1=0;i1<=c[1];i1++)
                        for(int i2=0;i2<=c[2];i2++) {
                                for(int j=0;j<3;j++) {
                                        ll v=dp[i0][i1][i2][j];
                                        for(int k=0;k<3;k++) if(j!=k) {
                                                int i[3]={i0,i1,i2};
                                                ll u = v;
                                                for(int l=0;l<3;l++)u += max(0, cnt[k][i[k]][l] - i[l]);
                                                i[k]++;
                                                for(int ii=0;ii<3;ii++)if(i[ii]>c[ii])goto dont;
                                                chmin(dp[i[0]][i[1]][i[2]][k],u);
                                                dont:;
                                        }
                                }
        }
        ll mn = infl;
        for(int k=0;k<3;k++) chmin(mn,dp[c[0]][c[1]][c[2]][k]);
        if(mn >= infl>>1)printf("-1\n");
        else printf("%lld\n",mn);
}
// then to optimize this, we can consider trying everything at once
// so dp[ra][ga][ba][current symbol] will trivialize this
// why didn't i think of this hadsfhlaksdhflkasdjalkfjslkdajflkadsj

Compilation message (stderr)

joi2019_ho_t3.cpp: In function 'int main()':
joi2019_ho_t3.cpp:23:24: warning: array subscript has type 'char' [-Wchar-subscripts]
   23 |                 pos[s[i]][c[s[i]]]=i;
      |                     ~~~^
joi2019_ho_t3.cpp:23:32: warning: array subscript has type 'char' [-Wchar-subscripts]
   23 |                 pos[s[i]][c[s[i]]]=i;
      |                             ~~~^
joi2019_ho_t3.cpp:25:32: warning: array subscript has type 'char' [-Wchar-subscripts]
   25 |                         cnt[s[i]][c[s[i]]][k]=c[k];
      |                             ~~~^
joi2019_ho_t3.cpp:25:40: warning: array subscript has type 'char' [-Wchar-subscripts]
   25 |                         cnt[s[i]][c[s[i]]][k]=c[k];
      |                                     ~~~^
joi2019_ho_t3.cpp:26:22: warning: array subscript has type 'char' [-Wchar-subscripts]
   26 |                 c[s[i]]++;
      |                   ~~~^
joi2019_ho_t3.cpp:18:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |         scanf("%d %s",&n,s);
      |         ~~~~~^~~~~~~~~~~~~~

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