oj.uz

Submission #222525

# Submission time Handle Problem Language Result Execution time Memory
222525 2020-04-13T08:44:53 Z _7_7_ Lamps (JOI19_lamps) C++14
0 / 100
 7 ms 640 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] - '0'; 
		b[i] = t[i] - '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) {
			if (b[i] == c[i])
				continue;
			int j = i;
			while (j + 1 < n && b[j + 1] == b[j])
				++j;

			++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();
    if (x1 != x2)
    	assert(x1 < x2);
	cout << x2 << endl;
}

Compilation message

lamp.cpp:108:7: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main () {
       ^
lamp.cpp: In function 'int main()':
lamp.cpp:109:7: 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 Runtime error 6 ms 512 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -

Subtask #2
0 / 41.0

# Verdict Execution time Memory Grader output
1 Runtime error 6 ms 512 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 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 Runtime error 7 ms 640 KB Execution killed with signal 11 (could be triggered by violating memory limits)
3 Halted 0 ms 0 KB -

Subtask #4
0 / 49.0

# Verdict Execution time Memory Grader output
1 Runtime error 6 ms 512 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -