Submission #632004

#	Time	Username	Problem	Language	Result	Execution time	Memory
632004		radal	Lamps (JOI19_lamps)	C++17	0 / 100	9 ms	5364 KiB

lamp

#include <bits/stdc++.h>
#define rep(i,l,r) for (int i = l; i < r; i++)
#define repr(i,r,l) for (int i = r; i >= l; i--)
#define pb push_back
#define X first
#define Y second
#define debug(x) cerr << #x << " : " << x << endl;
#define all(x) x.begin() , x.end()

using namespace std;

typedef pair<int,int> pll;
typedef long long ll;

constexpr int N = 2e3+10;

int cal[N][5],a[N][3],dp[N],pd[N][N][3];

int main(){
    ios_base :: sync_with_stdio(0); cin.tie(0);
    int n;
    cin >> n;
    string s,t;
    cin >> s >> t;
    s = '#'+s;
    t = '#'+t;


    cal[0][0] = 1;
    cal[0][1] = 1;
    cal[0][2] = 1;
    rep(i,1,n+1){
        rep(j,0,5){
            if (j == 3) continue;
            if (j == 4){
                if (s[i] == t[i]){
                    cal[i][j] = cal[i-1][3];
                    continue;
                }
                cal[i][j] = min(cal[i-1][2],cal[i-1][t[i]-'0']);
                continue;
            }
            if (j == 2){
                if (s[i] == t[i]){
                    cal[i][j] = min({cal[i-1][s[i]-'0']+1,cal[i-1][j]+1,2+cal[i-1][3]});
                    continue;
                }
                cal[i][j] = min(cal[i-1][j],cal[i-1][3]+1);
                continue;
            }
            else{
                if (j+'0' == t[i]){
                    cal[i][j] = min(cal[i-1][j],cal[i-1][3]+1);
                    continue;
                }
                cal[i][j] = min(cal[i-1][j]+1,cal[i-1][3]+2);
                continue;
            }
        }
        cal[i][3] = min({cal[i][0],cal[i][1],cal[i][2],cal[i][4]});
    }

    rep(i,1,n+1){
        if (t[i] == '1') a[i][1] = 1+a[i-1][1];
        else a[i][0] = 1+a[i-1][0];
    }
    repr(l,n,1){
        rep(r,l,n+1){
            if (t[r] == '1'){
                pd[l][r][1] = pd[l][r-1][1];
                if (a[r][1] >= r-l+1){
                    pd[l][r][0] = 1;
                    continue;
                }
                pd[l][r][0] = pd[l][r-a[r][1]][0]+1;
            }
            else{
                pd[l][r][0] = pd[l][r-1][0];
                if (a[r][0] >= r-l+1){
                    pd[l][r][1] = 1;
                    continue;
                }
                pd[l][r][1] = pd[l][r-a[r][0]][1]+1;
            }
        }
    }
    rep(i,1,n+1){
        if (s[i] == t[i]){
            dp[i] = dp[i-1];
            continue;
        }
        dp[i] = 1+dp[i-1];
        bool fl = 1;
        repr(j,i-1,1){
            fl &= (s[j] != t[j]);
            dp[i] = min(dp[i],dp[j-1]+min(pd[j][i][0],pd[j][i][1])+1);
            if (fl) dp[i] = min(dp[i],dp[j-1]+1);
        }
    }

    cout << min(dp[n],cal[n][3]);
}

• Subtask 1: 0 / 6
• Subtask 2: 0 / 41
• Subtask 3: 0 / 4
• Subtask 4: 0 / 49