Submission #105172

#	Time	Username	Problem	Language	Result	Execution time	Memory
105172		reality	Lamps (JOI19_lamps)	C++17	100 / 100	397 ms	35704 KiB

lamp

#include "bits/stdc++.h"
using namespace std;
#define fi first
#define se second
#define ll long long
#define dbg(v) cerr<<#v<<" = "<<v<<'\n'
#define vi vector<int>
#define vl vector <ll>
#define pii pair<int,int>
#define vii vector < pii >
#define mp make_pair
#define db long double
#define pb push_back
#define all(s) s.begin(),s.end()
template < class P , class Q > ostream& operator<<(ostream& stream, pair < P , Q > v){ stream << "(" << v.fi << ',' << v.se << ")"; return stream;}
template < class T > ostream& operator<<(ostream& stream, const vector<T> v){ stream << "[ "; for (int i=0; i<(int)v.size(); i++) stream << v[i] << " "; stream << "]"; return stream;}
template < class T > T smin(T &a,T b) {if (a > b) a = b;return a;}
template < class T > T smax(T &a,T b) {if (a < b) a = b;return a;}
const int N = 1e6 + 5;
const int oo = 1e9;
char A[N];
char B[N];
int dp[N][2][2][2];
int main(void) {
    int n;
    cin>>n;
    cin>>(A+1)>>(B+1);
    for (int i = 0;i <= n;++i)
    	for (int a = 0;a < 2;++a)
    		for (int b = 0;b < 2;++b)
    			for (int c = 0;c < 2;++c)
    				dp[i][a][b][c] = oo;
    dp[0][0][0][0] = 0;
    for (int i = 1;i <= n;++i) {
    	for (int a = 0;a < 2;++a)
    		for (int b = 0;b < 2;++b)
    			if (!a || !b)
    				for (int c = 0;c < 2;++c)
    					for (int d = 0;d < 2;++d)
    						if (!c || !d)
    							for (int e = 0;e < 2;++e) 
	    							for (int f = 0;f < 2;++f) {
	    								if (c) {
	    									if ((B[i] == '0') ^ e ^ 1) {
	    										continue;
	    									}
	    								} else
	    								if (d) {
	    									if ((B[i] == '1') ^ e ^ 1) {
	    										continue;
	    									}
	    								} else
	    								if (!c && !d) {
	    									if ((A[i] == B[i]) ^ e ^ 1) {
	    										continue;
	    									}
	    								}
	    								smin(dp[i][c][d][e],dp[i - 1][a][b][f] + (c && c != a) + (d && d != b) + (e && e != f));
	    							}
    }
    int ans = oo;
    for (int a = 0;a < 2;++a)
    	for (int b = 0;b < 2;++b)
    		for (int c = 0;c < 2;++c)
    			smin(ans,dp[n][a][b][c]);
    cout << ans << '\n';
    return 0;
}

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