Submission #1151028

#	Time	Username	Problem	Language	Result	Execution time	Memory
1151028		weakweakweak	Lamps (JOI19_lamps)	C++20	0 / 100	5 ms	4500 KiB

lamp

#include <bits/stdc++.h>
using namespace std;

int n;
string a, b;
int dp[2100][2][3] = {0};

int main() {
    ios_base::sync_with_stdio(false); cin.tie(0);
    cin >> n >> a >> b;
    for (char &c : a) c -= '0';
    for (char &c : b) c -= '0';
    a = "$"+a, b = "$"+b;
    memset(dp, 63, sizeof(dp));
    dp[0][0][2] = 0;

    for (int i = 1; i <= n; i++) {
        for (int lst = 0; lst <= 2; lst++) {
            if (a[i] == b[i]) {
                int z = min(dp[i-1][1][lst], dp[i-1][0][lst]);
                dp[i][0][2] = min(dp[i][0][2], z);
            }
            if (b[i] == 0) {
                dp[i][0][0] = min(dp[i][0][0], dp[i-1][0][lst] + !(lst==0));
                dp[i][1][0] = min(dp[i][1][0], dp[i-1][1][lst] + !(lst==0));
                dp[i][1][0] = min(dp[i][1][0], dp[i-1][0][1]+1 );
            }
            if (b[i] == 1) {
                dp[i][0][1] = min(dp[i][0][1], dp[i-1][0][lst] + !(lst==1));
                dp[i][1][1] = min(dp[i][1][1], dp[i-1][1][lst] + !(lst==1));
                dp[i][1][1] = min(dp[i][1][1], dp[i-1][0][0]+1 );

            }
            if (a[i] != b[i]) {
                for (int j = i; j <= n and b[j] != a[j]; j++) dp[j][1][2] = min(dp[j][1][2], min(dp[i-1][1][lst], dp[i-1][0][lst]+1));
            }
        } 
    }

    int ans = INT_MAX;
    for (int j = 0; j < 3; j++) {
        // cout << dp[n][0][j] << ' ' << dp[n][1][j] << '\n';
        ans = min(ans, min(dp[n][0][j], dp[n][1][j]));
    }
    cout << ans << '\n';
}
/*
5
01100
11001


01100
11110
11001

5
00110
01111
10011
*/

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