oj.uz

Submission #376186

# Submission time Handle Problem Language Result Execution time Memory
376186 2021-03-11T03:42:06 Z Kevin_Zhang_TW Lamps (JOI19_lamps) C++17
4 / 100
 25 ms 21996 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define pb emplace_back
#define AI(i) begin(i), end(i)
template<class T> bool chmin(T &a, T b) { return b < a && (a = b, true); }
template<class T> bool chmax(T &a, T b) { return a < b && (a = b, true); }
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void kout() { cerr << endl; }
template<class T, class ...U> void kout(T a, U ...b) { cerr << a << ' ', kout(b...); }
template<class T> void debug(T l, T r) { while (l != r) cerr << *l << " \n"[next(l) == r], ++l; }
#else
#define DE(...) 0
#define debug(...) 0
#endif
const int MAX_N = 1000010, inf = 1e9;

int n;
char a[MAX_N], b[MAX_N];
int va[MAX_N], vb[MAX_N], pfa[MAX_N], pfb[MAX_N], dp[MAX_N], dif[MAX_N];

int bst[2], good;

int32_t main() {
	ios_base::sync_with_stdio(0), cin.tie(0);
	cin >> n >> a+1 >> b+1;
	for (int i = 1;i <= n;++i) a[i] -= '0', b[i] -= '0';
	++n;
	for (int i = n;i >= 1;--i) {
		va[i] = a[i] ^ a[i-1];
		vb[i] = b[i] ^ b[i-1];
	}

	for (int i = 1;i <= n;++i) {
		pfa[i] = pfa[i-1] + va[i];
		pfb[i] = pfb[i-1] + vb[i];
		dif[i] = dif[i-1] + (va[i] != vb[i]);
	}

	if (accumulate(va, va+n+1, 0) == 0)
		return cout << accumulate(vb, vb + n + 1, 0) / 2 << '\n', 0;

	bst[0] = bst[1] = good = inf;

	for (int i = 1;i <= n;++i) {
		dp[i] = dif[i] + 1;

		chmin(dp[i], (va[i]==vb[i]) + pfb[i-1] 
				+ bst[ a[i-1] ]);
//		for (int j = 0;j < i;++j) {
//			if ( a[i-1] == a[j+1] ) {
//				// dp[j] + 2 + (va[j+1] == vb[j+1])  - pfb[j+1] + (va[i]==vb[i]) + pfb[i-1]
//				chmin(dp[i], dp[j] + 2 +
//						(va[i]==vb[i]) + (va[j+1]==vb[j+1]) + (pfb[i-1] - pfb[j+1]));
//			}
//		}

		chmin(dp[i], dif[i] + good);

		chmin(good, dp[i] - dif[i]);

		chmin(bst[ a[i+1] ],
				dp[i] + 2 + (va[i+1]==vb[i+1]) - pfb[i+1]);

	}

	cout << dp[n] / 2 << '\n';
}

Compilation message

lamp.cpp: In function 'int32_t main()':
lamp.cpp:27:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   27 |  cin >> n >> a+1 >> b+1;
      |              ~^~
lamp.cpp:27:22: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   27 |  cin >> n >> a+1 >> b+1;
      |                     ~^~
lamp.cpp:50:17: warning: array subscript has type 'char' [-Wchar-subscripts]
   50 |     + bst[ a[i-1] ]);
      |            ~~~~~^
lamp.cpp:63:19: warning: array subscript has type 'char' [-Wchar-subscripts]
   63 |   chmin(bst[ a[i+1] ],
      |              ~~~~~^

Subtask #1
0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 1 ms 384 KB Output is correct
8 Correct 1 ms 376 KB Output is correct
9 Correct 1 ms 364 KB Output is correct
10 Correct 1 ms 364 KB Output is correct
11 Correct 1 ms 364 KB Output is correct
12 Correct 1 ms 364 KB Output is correct
13 Correct 1 ms 364 KB Output is correct
14 Correct 1 ms 364 KB Output is correct
15 Correct 1 ms 364 KB Output is correct
16 Correct 1 ms 364 KB Output is correct
17 Correct 1 ms 364 KB Output is correct
18 Correct 1 ms 364 KB Output is correct
19 Correct 1 ms 364 KB Output is correct
20 Correct 1 ms 364 KB Output is correct
21 Correct 1 ms 364 KB Output is correct
22 Correct 1 ms 364 KB Output is correct
23 Correct 1 ms 364 KB Output is correct
24 Correct 1 ms 364 KB Output is correct
25 Correct 1 ms 364 KB Output is correct
26 Incorrect 1 ms 364 KB Output isn't correct
27 Halted 0 ms 0 KB -

Subtask #2
0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 1 ms 384 KB Output is correct
8 Correct 1 ms 376 KB Output is correct
9 Correct 1 ms 364 KB Output is correct
10 Correct 1 ms 364 KB Output is correct
11 Correct 1 ms 364 KB Output is correct
12 Correct 1 ms 364 KB Output is correct
13 Correct 1 ms 364 KB Output is correct
14 Correct 1 ms 364 KB Output is correct
15 Correct 1 ms 364 KB Output is correct
16 Correct 1 ms 364 KB Output is correct
17 Correct 1 ms 364 KB Output is correct
18 Correct 1 ms 364 KB Output is correct
19 Correct 1 ms 364 KB Output is correct
20 Correct 1 ms 364 KB Output is correct
21 Correct 1 ms 364 KB Output is correct
22 Correct 1 ms 364 KB Output is correct
23 Correct 1 ms 364 KB Output is correct
24 Correct 1 ms 364 KB Output is correct
25 Correct 1 ms 364 KB Output is correct
26 Incorrect 1 ms 364 KB Output isn't correct
27 Halted 0 ms 0 KB -

Subtask #3
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 23 ms 21996 KB Output is correct
8 Correct 25 ms 21868 KB Output is correct
9 Correct 21 ms 21868 KB Output is correct
10 Correct 21 ms 21868 KB Output is correct
11 Correct 21 ms 21868 KB Output is correct
12 Correct 21 ms 21868 KB Output is correct
13 Correct 21 ms 21868 KB Output is correct
14 Correct 21 ms 21868 KB Output is correct

Subtask #4
0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 1 ms 384 KB Output is correct
8 Correct 1 ms 376 KB Output is correct
9 Correct 1 ms 364 KB Output is correct
10 Correct 1 ms 364 KB Output is correct
11 Correct 1 ms 364 KB Output is correct
12 Correct 1 ms 364 KB Output is correct
13 Correct 1 ms 364 KB Output is correct
14 Correct 1 ms 364 KB Output is correct
15 Correct 1 ms 364 KB Output is correct
16 Correct 1 ms 364 KB Output is correct
17 Correct 1 ms 364 KB Output is correct
18 Correct 1 ms 364 KB Output is correct
19 Correct 1 ms 364 KB Output is correct
20 Correct 1 ms 364 KB Output is correct
21 Correct 1 ms 364 KB Output is correct
22 Correct 1 ms 364 KB Output is correct
23 Correct 1 ms 364 KB Output is correct
24 Correct 1 ms 364 KB Output is correct
25 Correct 1 ms 364 KB Output is correct
26 Incorrect 1 ms 364 KB Output isn't correct
27 Halted 0 ms 0 KB -