Submission #685073

#	Time	Username	Problem	Language	Result	Execution time	Memory
685073		Do_you_copy	Lamps (JOI19_lamps)	C++17	100 / 100	55 ms	16008 KiB

lamp

//Then
#include <bits/stdc++.h>
#define pb push_back
#define fi first
#define se second
#define faster ios_base::sync_with_stdio(0); cin.tie(0);

using namespace std;
using ll = long long;
using ld = long double;
using pii = pair <int, int>;
mt19937_64 Rand(chrono::steady_clock::now().time_since_epoch().count());
const int maxN = 1e6 + 1;
//const int Mod = 1e9 + 7;
//const int inf =
int n;
int dp[maxN][3];
string a, b;

char conv(char c, int i){
    if (i < 2) return i + '0';
    return c;
}

void Init(){
    cin >> n;
    string a, b;
    cin >> a >> b;
    a = " " + a;
    b = " " + b;
    memset(dp, 0x3f, sizeof(dp));
    dp[0][2] = 0;
    for (int i = 1; i <= n; ++i){
        for (int j = 0; j < 3; ++j){
            for (int k = 0; k < 3; ++k){
                int tem = dp[i - 1][j];
                if (j != k && k < 2) ++tem;
                if ((i == 1 || conv(a[i - 1], j) == b[i - 1]) && conv(a[i], k) != b[i]) ++tem;
                dp[i][k] = min(dp[i][k], tem);
            }
        }
    }
    cout << min({dp[n][0], dp[n][1], dp[n][2]});
}

#define debug
#define taskname "test"
signed main(){
    faster
    if (fopen(taskname".inp", "r")){
        freopen(taskname".inp", "r", stdin);
        freopen(taskname".out", "w", stdout);
    }
    int tt = 1;
    //cin >> tt;
    while (tt--){
        Init();
    }
    if (fopen("timeout.txt", "r")){
        ofstream timeout("timeout.txt");
        timeout << signed(double(clock()) / CLOCKS_PER_SEC * 1000);
        timeout.close();
        #ifndef debug
        cerr << "Time elapsed: " << signed(double(clock()) / CLOCKS_PER_SEC * 1000) << "ms\n";
        #endif // debug
    }
}

Compilation message (stderr)

lamp.cpp: In function 'int main()':
lamp.cpp:51:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |         freopen(taskname".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
lamp.cpp:52:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |         freopen(taskname".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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