Submission #341403

#	Time	Username	Problem	Language	Result	Execution time	Memory
341403		ryansee	Monochrome Points (JOI20_monochrome)	C++14	0 / 100	1 ms	364 KiB

monochrome

#include "bits/stdc++.h"
using namespace std;

#define FAST ios_base::sync_with_stdio(false); cin.tie(0);
#define pb push_back
#define eb emplace_back
#define ins insert
#define f first
#define s second
#define cbr cerr<<"hi\n"
#define mmst(x, v) memset((x), v, sizeof ((x)))
#define siz(x) ll(x.size())
#define all(x) (x).begin(), (x).end()
#define lbd(x,y) (lower_bound(all(x),y)-x.begin())
#define ubd(x,y) (upper_bound(all(x),y)-x.begin())
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());    //can be used by calling rng() or shuffle(A, A+n, rng)
inline long long rand(long long x, long long y) { return rng() % (y+1-x) + x; } //inclusivesss
string inline to_string(char c) {string s(1,c);return s;} template<typename T> inline T gcd(T a,T b){ return a==0?llabs(b):gcd(b%a,a); }

using ll=long long; 
using ld=long double;
#define FOR(i,s,e) for(ll i=s;i<=ll(e);++i)
#define DEC(i,s,e) for(ll i=s;i>=ll(e);--i)
using pi=pair<ll,ll>; using spi=pair<ll,pi>; using dpi=pair<pi,pi>; 

long long LLINF = 1e18;
int INF = 1e9+1e6;
#define MAXN (400006)
ll n, b, w, ans;
string A;
deque<ll> B, W;
int main() {
	FAST
	cin>>n>>A; n *= 2;
	b = count(all(A), 'B'), w = count(all(A), 'W');
	FOR(i,0,n-1) if(A[i] == 'B') {
		-- b;
		if(W.size() > b) { // must merge
			ll minus = lbd(B, W[0]);
			W.pop_front();
			ans += siz(W) + siz(B) - minus;
		} else {
			B.eb(i);
		}
		if(B.size() > w) {
			assert(0);
		}
	} else {
		-- w;
		if(B.size() > w) {
			ll minus = lbd(W, B[0]);
			B.pop_front();
			ans += siz(W) + siz(B) - minus;
		} else {
			W.eb(i);
		}
		if(W.size() > b) {
			assert(0);
		}
	}
	assert(W.empty() && B.empty());
	cout<<ans<<'\n';
}

Compilation message (stderr)

monochrome.cpp: In function 'int main()':
monochrome.cpp:38:15: warning: comparison of integer expressions of different signedness: 'std::deque<long long int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   38 |   if(W.size() > b) { // must merge
      |      ~~~~~~~~~^~~
monochrome.cpp:45:15: warning: comparison of integer expressions of different signedness: 'std::deque<long long int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   45 |   if(B.size() > w) {
      |      ~~~~~~~~~^~~
monochrome.cpp:50:15: warning: comparison of integer expressions of different signedness: 'std::deque<long long int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   50 |   if(B.size() > w) {
      |      ~~~~~~~~~^~~
monochrome.cpp:57:15: warning: comparison of integer expressions of different signedness: 'std::deque<long long int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   57 |   if(W.size() > b) {
      |      ~~~~~~~~~^~~

• Subtask 1: 0 / 4
• Subtask 2: 0 / 21
• Subtask 3: 0 / 10
• Subtask 4: 0 / 65