Submission #398470

#	Time	Username	Problem	Language	Result	Execution time	Memory
398470		qwerasdfzxcl	Lamps (JOI19_lamps)	C++14	4 / 100	34 ms	12184 KiB

lamp

#include <bits/stdc++.h>

typedef long long ll;
using namespace std;
string x, y;
int dp[1001000][2];

int main(){
    cin.tie(NULL);
    ios_base::sync_with_stdio(false);
    int n;
    string tmpx, tmpy;
    cin >> n >> tmpx >> tmpy;
    int idx1=0, idx2=n;
    for (;idx1<n && tmpx[idx1]==tmpy[idx1];idx1++);
    for (;idx2 && tmpx[idx2-1]==tmpy[idx2-1];idx2--);
    for (int i=idx1;i<idx2;i++) x.push_back(tmpx[i]);
    for (int i=idx1;i<idx2;i++) y.push_back(tmpy[i]);
    n = idx2-idx1;
    //cout << n << '\n' << x << '\n' << y << '\n';
    int pt[2] = {-2, -2}, pt2=-2;
    if (x[0]!=y[0]) dp[0][0]=1, pt2=0;
    dp[0][1] = 1;
    pt[y[0]-'0']=0;
    for (int i=1;i<n;i++){
        if (x[i]==y[i]) dp[i][0]=min(dp[i-1][0], dp[i-1][1]);
        else{
            if (x[i-1]!=y[i-1]) dp[i][0] = min(dp[i-1][0], dp[i-1][1]+1);
            else if (pt2==-2) dp[i][0] = 1;
            else dp[i][0] = min(min(dp[i-1][0], dp[i-1][1]), dp[pt2][0])+1;
            pt2=i;
        }
        if (y[i-1]==y[i]) dp[i][1] = min(dp[i-1][1], dp[i-1][0]+1), pt[y[i]-'0']=i;
        else{
            if (pt[y[i]-'0']==-2) dp[i][1] = min(dp[i-1][0], dp[i-1][1])+1;
            else dp[i][1] = min(min(dp[i-1][0], dp[i-1][1]), dp[pt[y[i]-'0']][1])+1;
            pt[y[i]-'0']=i;
        }
        dp[i][1] = min(dp[i][1], dp[i][0]+1);
    }
    /*for (int i=0;i<n;i++) cout << dp[i][0] << ' ';
    cout << '\n';
    for (int i=0;i<n;i++) cout << dp[i][1] << ' ';
    cout << '\n';*/
    if (n>=1) cout << min(dp[n-1][0], dp[n-1][1]);
    else cout << 0;
    return 0;
}

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