Submission #834870

#	Time	Username	Problem	Language	Result	Execution time	Memory
834870		Ozy	Lamps (JOI19_lamps)	C++17	0 / 100	7 ms	6640 KiB

lamp

#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i = (a); i <= (b); i++)
#define repa(i,a,b) for(int i = (a); i >= (b); i--)
#define lli long long int
#define debug(a) cout << #a << " = " << a << endl
#define debugsl(a) cout << #a << " = " << a << ", "
#define pll pair<lli,lli>

#define MAX 2000
#define INF (1ll<<60)

string st,fin;
lli n,a,b;
lli cambios[MAX+2],arr[MAX+2],dp[MAX+2],xors[MAX+2];

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> n >> st >> fin;

    rep(i,2,n) { //primero hare el de los cambios
        cambios[i] = cambios[i-1];
        if(fin[i-2] != fin[i-1]) cambios[i]++; 
    }

    rep(i,1,n) { //ahora el de los xors
        arr[i] = abs(st[i-1] - fin[i-1]);
        xors[i] = xors[i-1];
        if(arr[i] == 1 && arr[i-1] == 0) xors[i]++; 
    }

    rep(i,1,n) {
        dp[i] = INF;
        repa(j,i,1) {

            a = xors[i] - xors[j];
            if (arr[j]) a++;

            b = cambios[i] - cambios[j];
            b = 1 + (b+1)/2; 

            dp[i] = min(dp[i], dp[j-1] + min(a,b));
        }
        //debug(dp[1]);
    }

    cout << dp[n];

    return 0;  
}

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