Submission #172595

#	Time	Username	Problem	Language	Result	Execution time	Memory
172595		Pancake	Lamps (JOI19_lamps)	C++14	0 / 100	1037 ms	14628 KiB

lamp

#pragma GCC target("avx2")
#pragma GCC optimize("O3")
 
#include <x86intrin.h>
#include <bits/stdc++.h>   
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace __gnu_pbds;
using namespace std;

template<typename T> using ordered_set = tree <T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
     
#define F first
#define S second           
#define lb lower_bound               
#define ub upper_bound
#define pb push_back
#define pf push_front    
#define ppb pop_back
#define mp make_pair                                     
#define bpp __builtin_popcountll                                                                                        
#define sqr(x) ((x) * (x)) 
#define al 0x3F3F3F3F
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define in insert
#define ppf pop_front
#define endl '\n'
//#define int long long
 
typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
typedef pair <int, int> pii;
 
const int mod = (int)1e9 + 7;
const int N = (int)3e5 + 123;
const ll inf = (ll)1e18 + 1;

const double pi = acos (-1.0);
const double eps = 1e-7;                  
const int dx[] = {0, 0, 1, 0, -1};
const int dy[] = {0, 1, 0, -1, 0};

int n, cost[2002][2002][4], dp[2002], pref[2002][3];
char a[N], b[N];

inline int get (int l, int r, int t) {
   return pref[r][t] - pref[l - 1][t];
}

inline void boost () {                    
   ios_base :: sync_with_stdio (NULL);
   cin.tie (NULL), cout.tie (NULL);          
}                                                     

inline void Solve () {
   cin >> n >> a + 1 >> b + 1;
   for (int i = 1; i <= n; i ++) pref[i][0] = pref[i - 1][0] + (b[i] == '0'), pref[i][1] = pref[i - 1][1] + (b[i] == '1'), dp[i] = mod;
   for (int i = 1; i <= n; i ++) {
      int ans1 = 0, last1 = -1;
      int ans2 = 0, last2 = -1;
      for (int j = i; j <= n; j ++) {
         if (a[j] == b[j]) {
            if (last1 != -1 && get (last1, j, b[j] - '0') == j - last1 + 1)
               last1 = j;
            else 
               ans1 ++, last1 = j;
         }
         else {
            if (last2 != -1 && get (last2, j, b[j] - '0') == j - last2 + 1)
               last2 = j;
            else 
               ans2 ++, last2 = j;
         }
         dp[j] = min (dp[j], dp[i - 1] + 1 + ans1);
         dp[j] = min (dp[j], dp[i - 1] + ans2);
      }
      //cout << dp[i] << ' ';
   }
   cout << dp[n];
}

main () {                                       
// freopen (".in", "r", stdin);    
// freopen (".out", "w", stdout);              
   boost ();
   int tt = 1;
   //cin >> tt;   
   while (tt --) {
      Solve ();
   }                                               
   return 0;      
}
                          

Compilation message (stderr)

lamp.cpp: In function 'void Solve()':
lamp.cpp:59:18: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
    cin >> n >> a + 1 >> b + 1;
                ~~^~~
lamp.cpp:59:27: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
    cin >> n >> a + 1 >> b + 1;
                         ~~^~~
lamp.cpp: At global scope:
lamp.cpp:85:7: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main () {                                       
       ^

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