Submission #792462

#	Time	Username	Problem	Language	Result	Execution time	Memory
792462		vjudge1	Lamps (JOI19_lamps)	C++17	100 / 100	152 ms	27800 KiB

lamp

#include <bits/stdc++.h>
 
#define fi first
#define se second
 
const int N = 1000010;
 
using namespace std;
 
int n;
int A[N], B[N], C[N], D[N];
char a[N], b[N];
int d[N][3][2];
 
void upd(int &x, int y)
{
        x = min(x, y);
}
 
int main()
{
        ios_base::sync_with_stdio(0);
 
        //freopen("input.txt", "r", stdin);
        //freopen("output.txt", "w", stdout);
 
        cin >> n;
        for(int i = 1; i <= n; i++) cin >> a[i];
        for(int i = 1; i <= n; i++) cin >> b[i];
 
        int inf = 1e9;
        for(int i = 0; i < N; i++){
                for(int j = 0; j < 3; j++){
                        for(int h = 0; h < 2; h++){
                                d[i][j][h] = inf;
                        }
                }
        }
        d[0][0][0] = 0;
        for(int i = 1; i <= n; i++){
                for(int g1 = 0; g1 < 3; g1++){
                        for(int g2 = 0; g2 < 2; g2++){
                                upd(d[i][g1][g2], d[i - 1][g1][g2]);
                                upd(d[i][0][g2], d[i - 1][g1][g2]);
                                upd(d[i][g1][0], d[i - 1][g1][g2]);
                                upd(d[i][0][0], d[i - 1][g1][g2]);
                                if(g1 == 0){
                                        upd(d[i][1][g2], d[i - 1][g1][g2] + 1);
                                        upd(d[i][2][g2], d[i - 1][g1][g2] + 1);
                                        if(g2 == 0){
                                                upd(d[i][1][1], d[i - 1][g1][g2] + 2);
                                                upd(d[i][2][1], d[i - 1][g1][g2] + 2);
                                        }
                                }
                                if(g2 == 0){
                                        upd(d[i][g1][1], d[i - 1][g1][g2] + 1);
                                }
                        }
                }
                for(int g1 = 0; g1 < 3; g1++){
                        for(int g2 = 0; g2 < 2; g2++){
                                int cur = a[i] - '0', need = b[i] - '0';
                                if(g1 == 1) cur = 1;
                                else if(g1 == 2) cur = 0;
                                if(g2 == 1) cur ^= 1;
                                if(cur != need){
                                        d[i][g1][g2] = inf;
                                }
                        }
                }
        }
        int res = inf;
        for(int i = 0; i < 3; i++){
                for(int j = 0; j < 2; j++){
                        res = min(res, d[n][i][j]);
                }
        }
        cout << res << "\n";
}

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