oj.uz

Submission #222531

# Submission time Handle Problem Language Result Execution time Memory
222531 2020-04-13T08:54:14 Z _7_7_ Lamps (JOI19_lamps) C++14
0 / 100
 60 ms 14080 KB 
#include <bits/stdc++.h>        	                                   
 
//#define int long long
//#pragma GCC optimize("Ofast")
//#pragma comment(linker, "/stack:200000000")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4")
 
 
#define file(s) freopen(s".in","r",stdin); freopen(s".out","w",stdout);
#define forev(i, b, a) for(int i = (b); i >= (a); --i)
#define forn(i, a, b) for(int i = (a); i <= (b); ++i)
#define all(x) x.begin(), x.end()
#define sz(s) (int)s.size()
#define pb push_back
#define ppb pop_back
#define mp make_pair
#define s second
#define f first
 
 
using namespace std;
 
 
typedef pair < long long, long long > pll;    
typedef pair < int, int > pii;
typedef unsigned long long ull;         
typedef vector < pii > vpii;
typedef vector < int > vi;
typedef long double ldb;  
typedef long long ll;  
typedef double db;                             
 
 
const int inf = 1e9, maxn = 4e5 + 148, mod = 1e9 + 7, N = 1e6 + 11;
const int dx[] = {1, -1, 0, 0}, dy[] = {0, 0, 1, -1}, block = 333;
const pii base = mp(1171, 3307), Mod = mp(1e9 + 7, 1e9 + 9);
const db eps = 1e-12, pi = 3.14159265359;
const ll INF = 1e18;
 
 
int n, dp[N][2], prv[N], a[N], b[N], c[N];
char s[N], t[N];

int solve1 () {
	for (int i = 1; i <= n; ++i) {
		prv[i] = i - 1;
		if (i > 1 && t[i] == t[i - 1])
			prv[i] = prv[i - 1];
	}	
		
 
	dp[0][1] = inf;
	int lst = 0;
	for (int i = 1; i <= n; ++i)
		if (s[i] == t[i]) {
			dp[i][0] = min({dp[i - 1][0], dp[i - 1][1], dp[prv[i]][0] + 1, dp[prv[i]][1] + 1});
			dp[i][1] = dp[prv[i]][1] + 1;
			lst = i;
		} else {
			dp[i][0] = min(dp[prv[i]][0], dp[prv[i]][1]) + 1;
			dp[i][1] = min(dp[lst][0] + 1, dp[lst][1]);
		}
	return min(dp[n][0], dp[n][1]);		
}

int solve2 () {
	for (int i = 0; i < n; ++i) {
		a[i] = s[i + 1] - '0'; 
		b[i] = t[i + 1] - '0';
	}

	int ans = inf;

	for (int mask = 0; mask < (1 << n); ++mask) {
		for (int i = 0; i < n; ++i)
			c[i] = a[i];


		int res = 0;
		for (int i = 0; i < n; ++i) {
			if (!(mask & (1 << i)))
				continue;
			int j = i;
			c[i] ^= 1;
			while (j + 1 < n && (mask & (1 << (j + 1)))) 
				c[++j] ^= 1;			
			++res;
			i = j;
		}		

		for (int i = 0; i < n; ++i) {
			bool ok = 0;
			
			int j = i;
			if (b[j] != c[j])
				ok = 1;

			while (j + 1 < n && b[j + 1] == b[j])  {
				++j;  
				if (b[j] != c[j])
					ok = 1;			
			}
			
			if (ok)
				++res;
			i = j;
		}
		ans = min(ans, res);
	}

	return ans;
}

 
main () {
	scanf("%d\n%s\n%s", &n, s + 1, t + 1);
//	int x1 = solve1(), x2 = solve2();
//	cerr << x1 << ' ' << x2 << endl;
	cout << solve2() << endl;
}

Compilation message

lamp.cpp:115:7: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main () {
       ^
lamp.cpp: In function 'int main()':
lamp.cpp:116:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d\n%s\n%s", &n, s + 1, t + 1);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 384 KB Output is correct
2 Correct 4 ms 384 KB Output is correct
3 Correct 4 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct
5 Correct 4 ms 384 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 51 ms 384 KB Output is correct
9 Correct 60 ms 384 KB Output is correct
10 Correct 28 ms 384 KB Output is correct
11 Correct 27 ms 384 KB Output is correct
12 Correct 39 ms 384 KB Output is correct
13 Correct 22 ms 384 KB Output is correct
14 Correct 35 ms 384 KB Output is correct
15 Correct 21 ms 384 KB Output is correct
16 Incorrect 41 ms 384 KB Output isn't correct
17 Halted 0 ms 0 KB -

Subtask #2
0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 384 KB Output is correct
2 Correct 4 ms 384 KB Output is correct
3 Correct 4 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct
5 Correct 4 ms 384 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 51 ms 384 KB Output is correct
9 Correct 60 ms 384 KB Output is correct
10 Correct 28 ms 384 KB Output is correct
11 Correct 27 ms 384 KB Output is correct
12 Correct 39 ms 384 KB Output is correct
13 Correct 22 ms 384 KB Output is correct
14 Correct 35 ms 384 KB Output is correct
15 Correct 21 ms 384 KB Output is correct
16 Incorrect 41 ms 384 KB Output isn't correct
17 Halted 0 ms 0 KB -

Subtask #3
0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 384 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 5 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct
5 Correct 5 ms 384 KB Output is correct
6 Correct 4 ms 384 KB Output is correct
7 Correct 21 ms 13952 KB Output is correct
8 Correct 33 ms 14080 KB Output is correct
9 Incorrect 17 ms 10112 KB Output isn't correct
10 Halted 0 ms 0 KB -

Subtask #4
0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 384 KB Output is correct
2 Correct 4 ms 384 KB Output is correct
3 Correct 4 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct
5 Correct 4 ms 384 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 51 ms 384 KB Output is correct
9 Correct 60 ms 384 KB Output is correct
10 Correct 28 ms 384 KB Output is correct
11 Correct 27 ms 384 KB Output is correct
12 Correct 39 ms 384 KB Output is correct
13 Correct 22 ms 384 KB Output is correct
14 Correct 35 ms 384 KB Output is correct
15 Correct 21 ms 384 KB Output is correct
16 Incorrect 41 ms 384 KB Output isn't correct
17 Halted 0 ms 0 KB -