Submission #261533

#	Time	Username	Problem	Language	Result	Execution time	Memory
261533		mjkocijan	Lamps (JOI19_lamps)	C++14	100 / 100	202 ms	27772 KiB

lamp

#include <bits/stdc++.h>
using namespace std;
#define X first
#define Y second
#define pb push_back
typedef long long ll;
typedef pair<ll, ll> ii;
#define MAXN 1001001

int n;
char a[MAXN], b[MAXN];
int dp[MAXN][3][2], reza = MAXN;

int main()
{
	scanf("%d", &n);
	scanf("%s", a);
	scanf("%s", b);
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < 3; j++) {
			for (int k = 0; k < 2; k++) {
				dp[i][j][k] = MAXN;
				for (int l = 0; l < 3; l++) {
					for (int m = 0; m < 2; m++) {//cout << i <<' '<<j<<' '<<k<<'.'<<l<<' '<<m<<','<<dp[i][j][k]<<endl;
						if (i == 0 && (l || m)) continue;//cout<<'.';
						int bk;
						if (j)
							bk = (j - 1) ^ k;
						else
							bk = (a[i] - '0') ^ k;
						if (bk != b[i] - '0') continue;//cout<<'/';
						dp[i][j][k] = min(dp[i][j][k], (i ? dp[i - 1][l][m] : 0) + (j != l && j) * 2 + (k != m));
						if (i == n - 1) reza = min(reza, dp[i][j][k]);
					}
				}
				//cout << i << ' ' <<j <<' ' << k <<'.'<<dp[i][j][k]<<endl;
			}
		}
	}
	//cout << ceil(double(reza) / 2.0) << endl;
	printf("%d\n", (int)ceil(double(reza) / 2.0));
	return 0;
}

Compilation message (stderr)

lamp.cpp: In function 'int main()':
lamp.cpp:16:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
lamp.cpp:17:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s", a);
  ~~~~~^~~~~~~~~
lamp.cpp:18:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s", b);
  ~~~~~^~~~~~~~~

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