Submission #256132

#	Time	Username	Problem	Language	Result	Execution time	Memory
256132		muhammad_hokimiyon	Lamps (JOI19_lamps)	C++14	0 / 100	1084 ms	82608 KiB

lamp

#include <bits/stdc++.h>

//#pragma GCC optimize("Ofast")

#define fi first
#define se second
#define ll long long
#define dl double long

using namespace std;

const int NN = 1e9 + 7;
const int N = 1e6 + 7;
const int M = 4;
const ll mod = 1e9 + 7;
const int inf = 1e9 + 7;
const dl rf = 1e-14;
const int B = sqrt(N);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int n;
string s,b;
int f[N][4];
int d[N][M][M];
map < pair < pair < int , int > , int > , int > m;

void solve1()
{
    cin >> n >> s >> b;
    s = '#' + s;
    b = '#' + b;
    for( int i = 0; i <= n; i++ ){
        for( int j = 0; j < M; j++ ){
            for( int h = 0; h < M; h++ ){
                d[i][j][h] = 1e9;
            }
        }
    }
    for( int i = 1; i <= n; i++ ){
        f[i][1] = f[i - 1][1] + (b[i] == '0');
        f[i][2] = f[i - 1][2] + (b[i] == '1');
        f[i][3] = f[i - 1][3] + (b[i] != s[i]);
    }
    d[0][0][0] = 0;
    //m[{ {1 , 2} , 3 }] = 1;
    //m[{ {2 , 1} , 3 }] = 1;
    m[{ {3 , 1} , 2 }] = 1;
    m[{ {3 , 2} , 1 }] = 1;
    for( int i = 1; i <= n; i++ ){
        for( int j = 0; j < M; j++ ){
            if( b[i] == '0' ){
                int l = 1 , r = i;
                while( l < r ){
                    int m = (l + r) / 2;
                    if( f[i][1] - f[m - 1][1] == i - m + 1 )r = m;
                    else l = m + 1;
                }
                for( int h = 0; h <= 3; h++ ){
                    d[i][j][1] = min( d[i][j][1] , d[l - 1][h][j] + 1 - m[{{ h , j } ,  1}] );
                }
            }
            if( s[i] == b[i] ){
                for( int h = 0; h < M; h++ ){
                    d[i][j][0] = min( d[i][j][0] , d[i - 1][h][j] );
                }
            }else{
                int l = 1 , r = i;
                while( l < r ){
                    int m = (l + r) / 2;
                    if( f[i][3] - f[m - 1][3] == i - m + 1 )r = m;
                    else l = m + 1;
                }
                for( int h = 0; h < M; h++ ){
                    d[i][j][3] = min( d[i][j][3] , d[l - 1][h][j] + 1 - m[{{ h , j } ,  3}] );
                    if( i == 8 && j == 1 ){
                        //cout << l << " " << h << " " << j << " " << 3 << " " << d[l - 1][h][j] << "\n";
                    }
                }
            }
            if( b[i] == '1' ){
                int l = 1 , r = i;
                while( l < r ){
                    int m = (l + r) / 2;
                    if( f[i][2] - f[m - 1][2] == i - m + 1 )r = m;
                    else l = m + 1;
                }
                for( int h = 0; h < M; h++ ){
                    d[i][j][2] = min( d[i][j][2] , d[l - 1][h][j] + 1 - m[{{ h , j } ,  2}] );
                }
            }
           // cout << i << " " << j << " " << d[i][j][0] << " " << d[i][j][1] << " " << d[i][j][2] << " "
           //  << d[i][j][3] << "\n";
        }
    }
    int ans = 1e9;
    for( int i = 0; i <= 3; i++ ){
        for( int j = 0; j <= 3; j++ ){
            ans = min( ans , d[n][i][j] );
        }
    }
    for( int i = 0; i <= n; i++ ){
        for( int j = 0; j < M; j++ ){
            for( int h = 0; h < M; h++ ){
                d[i][j][h] = 1e9;
            }
        }
    }
    for( int i = 1; i <= n; i++ ){
        f[i][1] = f[i - 1][1] + (b[i] == '0');
        f[i][2] = f[i - 1][2] + (b[i] == '1');
        f[i][3] = f[i - 1][3] + (b[i] != s[i]);
    }
    d[0][0][0] = 0;
    m[{ {1 , 2} , 3 }] = 1;
    m[{ {2 , 1} , 3 }] = 1;
    m[{ {3 , 1} , 2 }] = 0;
    m[{ {3 , 2} , 1 }] = 0;
    for( int i = 1; i <= n; i++ ){
        for( int j = 0; j <= 3; j++ ){
            if( b[i] == '0' ){
                int l = 1 , r = i;
                while( l < r ){
                    int m = (l + r) / 2;
                    if( f[i][1] - f[m - 1][1] == i - m + 1 )r = m;
                    else l = m + 1;
                }
                for( int h = 0; h <= 3; h++ ){
                    d[i][j][1] = min( d[i][j][1] , d[l - 1][h][j] + 1 - m[{{ h , j } ,  1}] );
                }
            }
            if( s[i] == b[i] ){
                for( int h = 0; h <= 3; h++ ){
                    d[i][j][0] = min( d[i][j][0] , d[i - 1][h][j] );
                }
            }else{
                int l = 1 , r = i;
                while( l < r ){
                    int m = (l + r) / 2;
                    if( f[i][3] - f[m - 1][3] == i - m + 1 )r = m;
                    else l = m + 1;
                }
                for( int h = 0; h <= 3; h++ ){
                    d[i][j][3] = min( d[i][j][3] , d[l - 1][h][j] + 1 - m[{{ h , j } ,  3}] );
                    if( i == 8 && j == 1 ){
                        //cout << l << " " << h << " " << j << " " << 3 << " " << d[l - 1][h][j] << "\n";
                    }
                }
            }
            if( b[i] == '1' ){
                int l = 1 , r = i;
                while( l < r ){
                    int m = (l + r) / 2;
                    if( f[i][2] - f[m - 1][2] == i - m + 1 )r = m;
                    else l = m + 1;
                }
                for( int h = 0; h <= 3; h++ ){
                    d[i][j][2] = min( d[i][j][2] , d[l - 1][h][j] + 1 - m[{{ h , j } ,  2}] );
                }
            }
           // cout << i << " " << j << " " << d[i][j][0] << " " << d[i][j][1] << " " << d[i][j][2] << " "
           //  << d[i][j][3] << "\n";
        }
    }
    cout << ans;
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    //freopen( "input.txt" , "r" , stdin );
    //freopen( "output.txt" , "w" , stdout );

    int cghf = 1;//cin >> cghf;
    while( cghf-- ){
        solve1();
    }
}

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