Submission #874854

#	Time	Username	Problem	Language	Result	Execution time	Memory
874854		josanneo22	Miners (IOI07_miners)	C++17	100 / 100	88 ms	1116 KiB

miners

/*
Problem: IOI 2007 Miners 
When:    2023-11-13 21:27:07
Author:  JN
*/
#include<bits/stdc++.h>
using namespace std;
 
using i64 = long long;
using pii = pair<int, int>;
#define L(i,j,k) for(int i=(j);i<=(k);++i)
#define R(i,j,k) for(int i=(j);i>=(k);--i)
#define all(x) x.begin(), x.end()
 
int dp[2][4][4][4][4];
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);
 
    int n; cin>>n;
    string s; cin>>s;
    vector<int> a(n+1);
    L(i,0,n-1){
        if(s[i]=='M') a[i]=1;
        if(s[i]=='B') a[i]=2;
        if(s[i]=='F') a[i]=3;
    }
    memset(dp,-1,sizeof(dp));
    dp[0][0][0][0][0]=0;
    auto profit=[&](int x,int y,int z){
        if(!x && !y) return 1;
        if(!x) return (y!=z)+1;
        if(x==y && y==z) return 1;
        return (x!=y)+(y!=z)+(z!=x);
    };
    L(i,0,n-1){
        int nw=i&1;int nx=nw^1;
        L(a1,0,3) L(a2,0,3) L(b1,0,3) L(b2,0,3){
            if(dp[nw][a1][a2][b1][b2]==-1) continue;
            dp[nx][a2][a[i]][b1][b2]=max(dp[nx][a2][a[i]][b1][b2], dp[nw][a1][a2][b1][b2]+profit(a1,a2,a[i]));
            dp[nx][a1][a2][b2][a[i]]=max(dp[nx][a1][a2][b2][a[i]], dp[nw][a1][a2][b1][b2]+profit(b1,b2,a[i]));
            // cout<<a1<<' '<<a2<<' '<<b1<<' '<<b2<<' ';
            // cout<<profit(a1,a2,a[i])<<' ';
            // cout<<profit(b1,b2,a[i])<<'\n';
        }
    }
    int ans=0;
    L(a1,0,3) L(a2,0,3) L(b1,0,3) L(b2,0,3){
        if(ans<dp[n&1][a1][a2][b1][b2]){
            ans=dp[n&1][a1][a2][b1][b2];
            //cout<<a1<<' '<<a2<<' '<<b1<<' '<<b2<<'\n';
        }
    }
    cout<<ans<<'\n';
}

• Subtask 1: 9 / 9
• Subtask 2: 9 / 9
• Subtask 3: 9 / 9
• Subtask 4: 9 / 9
• Subtask 5: 9 / 9
• Subtask 6: 7 / 7
• Subtask 7: 8 / 8
• Subtask 8: 8 / 8
• Subtask 9: 8 / 8
• Subtask 10: 8 / 8
• Subtask 11: 8 / 8
• Subtask 12: 8 / 8