Submission #1158537

#	Time	Username	Problem	Language	Result	Execution time	Memory
1158537		dosts	Lamps (JOI19_lamps)	C++20	100 / 100	23 ms	14264 KiB

lamp

#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2")
using namespace std;
//#define int long long
#define pii pair<int,int>
#define ff first
#define ss second
#define sp << " " <<    
#define all(cont) cont.begin(),cont.end()
#define vi vector<int>

const int inf = 2e9,N = 4e5+1,MOD =  1e9+7;


void solve() {
    int n;
    cin >> n;
    string a,b;
    cin >> a >> b;
    for (auto& it : a) it-='0';
    for (auto& it : b) it-='0';
    int dp[n+1][3];
    for (int i = 0;i<=n;i++) for (int j = 0;j<3;j++) dp[i][j] = inf;
    dp[0][2] = 0;
    auto now = [&](int p,int t) {
        if (!p) return (int)(t==1);
        if (t == 1) return 1;
        if (t == 0) return 0;
        return (int)a[p-1];
    };
    for (int i = 0;i<n;i++) {
        for (int j = 0;j<=2;j++) {
            if (dp[i][j] == inf) continue;
            int swi = (i && (now(i,j) != b[i-1]));
            for (int jj = 0;jj<2;jj++) {
                dp[i+1][jj] = min(dp[i+1][jj],dp[i][j]+(j!=jj)+(now(i+1,jj)!=b[i] && !swi));
            }
            dp[i+1][2] = min(dp[i+1][2],dp[i][j]+(now(i+1,2)!=b[i] && !swi));
        }
    }
    int ans = inf;
    for (int j = 0;j<3;j++) ans = min(ans,dp[n][j]);
    cout << ans << '\n';
}


int32_t main() { 
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    #ifdef Dodi 
        freopen("in.txt","r",stdin);
        freopen("out.txt","w",stdout);
    #endif
    int t = 1;
    //cin >> t;
    while (t --> 0) solve();
}

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