Submission #1281905

#	Time	Username	Problem	Language	Result	Execution time	Memory
1281905		InvMOD	Lamps (JOI19_lamps)	C++17	100 / 100	42 ms	3480 KiB

lamp

#include<bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define pb push_back
#define eb emplace_back

#define vi vector<int>
#define pi pair<int,int>
#define sz(v) (int)(v).size()
#define all(v) (v).begin(), (v).end()
#define compact(v) (v).erase(unique(all(v)), (v).end())

template<class T> using upq = priority_queue<T, vector<T>, greater<T>>;
template<class T> int lwrbound(const vector<T>& a, const T& b, const int s = 0){return int(lower_bound(s + all(a), b) - a.begin());}
template<class T> int uprbound(const vector<T>& a, const T& b, const int s = 0){return int(upper_bound(s + all(a), b) - a.begin());}

#define FOR(i, a, b) for(int i = (a); i <= (b); i++)
#define ROF(i, a, b) for(int i = (a); i >= (b); i--)
#define sumof(x) accumulate(all(x), 0ll)
#define dbg(x) "[" << #x " = " << (x) << "]"
#define el "\n"

using ll = long long;
using ld = long double;

template<class T> bool ckmx(T& a, const T b){return (a < b ? a = b, true : false);}
template<class T> bool ckmn(T& a, const T b){return (a > b ? a = b, true : false);}


void Main()
{
    int n; cin >> n;

    string A, B; cin >> A >> B;

    A = " " + A;
    B = " " + B;

    vi dp(3, 1e9);
    (A[1] != B[1] ? dp[B[1] - '0'] = 1, dp[2] = 1 : dp[2] = 0);

    FOR(i, 2, n){
        vi ndp(3, 1e9);
        FOR(j, 0, 2){
            int p = (j < 2 ? j : A[i - 1] - '0');
            int pB = (B[i - 1] - '0');

            FOR(k, 0, 2){
                int x = (k < 2 ? k : A[i] - '0');
                int xB = (B[i] - '0');
                ckmn(ndp[k], dp[j] + (j == 2 && k < 2) + (p == pB && x != xB) + (max(j, k) < 2 && j != k));
            }
        }
        swap(dp, ndp);
   }

    cout << *min_element(all(dp)) << el;
}

int32_t main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    #define name "InvMOD"
    if(fopen(name".INP", "r")){
        freopen(name".INP", "r", stdin);
        freopen(name".OUT", "w", stdout);
    }

    int t = 1; while(t--) Main();
    return 0;
}

Compilation message (stderr)

lamp.cpp: In function 'int32_t main()':
lamp.cpp:70:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |         freopen(name".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
lamp.cpp:71:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   71 |         freopen(name".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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