Submission #102654

#	Time	Username	Problem	Language	Result	Execution time	Memory
102654		FutymyClone	Lamps (JOI19_lamps)	C++14	4 / 100	49 ms	31816 KiB

lamp

#include <bits/stdc++.h>

using namespace std;

const int N = 1e6 + 5;

int n, dp[N], a[N], b[N], c[N], lstb0[N], lstb1[N], lstc1[N];
string s, t;

int main(){
    ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    cin >> n >> s >> t; b[0] = -1;
    for (int i = 0; i < n; i++) {
        a[i + 1] = s[i] - '0';
        b[i + 1] = t[i] - '0';
        c[i + 1] = a[i + 1] ^ b[i + 1];
    }

    for (int i = 1; i <= n; i++) {
        if (b[i] == 1) lstb1[i] = (b[i - 1] == 1 ? lstb1[i - 1] : i);
        else lstb0[i] = (b[i - 1] == 0 ? lstb0[i - 1] : i);
        if (c[i] == 1) lstc1[i] = (c[i - 1] == 1 ? lstc1[i - 1] : i);
    }

    memset(dp, 0x3f, sizeof(dp)); dp[0] = 0;
    for (int i = 1; i <= n; i++) {
        dp[i] = dp[i - 1] + (a[i] == b[i] ? 0 : 1);
        if (lstb0[i]) dp[i] = min(dp[i], dp[lstb0[i] - 1] + 1);
        if (lstb1[i]) dp[i] = min(dp[i], dp[lstb1[i] - 1] + 1);
        if (lstc1[i]) dp[i] = min(dp[i], dp[lstc1[i] - 1] + 1);
    }

    //for (int i = 1; i <= n; i++) cout << dp[i] << " ";
    //cout << '\n';
    cout << dp[n];
    return 0;
}

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