#include <bits/stdc++.h>
using namespace std;
#define EmiliaMyWife ios::sync_with_stdio(0); cin.tie(0);
using ll = int64_t;
using ull = uint64_t;
using uint = uint32_t;
using ld = long double;
const int INF = 0x3f3f3f3f;
const ll LINF = ll(4e18) + ll(2e15);
const int MOD = 1e9 + 7;
const double EPS = 1e-8;
static int LamyIsCute = []() {
EmiliaMyWife
return 48763;
}();
pair<int, int> operator+(pair<int, int> a, pair<int, int> b) {
return make_pair(a.first + b.first, a.second + b.second);
}
pair<int, int> get_direction(char c) {
if(c == 'E')
return {1, 0};
if(c == 'W')
return {-1, 0};
if(c == 'N')
return {0, 1};
if(c == 'S')
return {0, -1};
return {0, 0};
}
pair<int, int> get_vector(const string &s) {
pair<int, int> res = {0, 0};
for(char c : s)
res = res + get_direction(c);
return res;
}
pair<int, int> simplify(string &s) {
auto [a, b] = get_vector(s);
if(a == 0) {
for(char &c : s) {
if(c == 'E')
c = 'N';
else if(c == 'W')
c = 'S';
else if(c == 'N')
c = 'E';
else // c == 'S'
c = 'W';
}
swap(a, b);
}
if(a < 0) {
for(char &c : s) {
if(c == 'E')
c = 'W';
else if(c == 'W')
c = 'E';
}
a = -a;
}
if(b < 0) {
for(char &c : s) {
if(c == 'S')
c = 'N';
else if(c == 'N')
c = 'S';
}
b = -b;
}
return {a, b};
}
int get_ans(const string &s) {
set<pair<int, int>> has;
pair<int, int> res = {0, 0};
has.insert(res);
for(char c : s) {
res = res + get_direction(c);
has.insert(res);
}
int ans = 0;
for(const auto &[a, b] : has)
ans += has.count({a, b + 1}) && has.count({a + 1, b}) && has.count({a + 1, b + 1});
return ans;
}
struct dat {
int p, q, l, r;
bool operator<(dat other) {
auto a = make_pair(p, q), b = make_pair(other.p, other.q);
if(a == b)
return l < other.l;
return a < b;
}
dat() { }
dat(int a, int b, int c, int d): p(a), q(b), l(c), r(d) { }
};
signed main() {
int n, k;
cin >> n >> k;
string s;
cin >> s;
auto [a, b] = simplify(s);
if(a == 0)
return cout << get_ans(s) << '\n', 0;
vector<dat> arr;
pair<int, int> res = {0, 0};
arr.push_back({0, 0, 0, 0});
arr.push_back({a, b, -1, -1});
for(char c : s) {
res = res + get_direction(c);
has.insert(res);
auto [x, y] = res;
int w = (x > 0) ? x / a : (x - a + 1) / a;
arr.push_back({x - a * w, y - b * w, w, w + k - 1});
if(x - a * w == 0) {
w--;
arr.push_back({x - a * w, y - b * w, w, w + k - 1});
}
}
sort(arr.begin(), arr.end());
ll ans = 0;
res = {-INF, -INF};
for(const auto &[x, y, _, __] : arr) {
if(make_pair(x, y) == res)
continue;
res = {x, y};
pair<int, int> pos[4] = {res, res + make_pair(0, 1), res + make_pair(1, 0), res + make_pair(1, 1)};
int it[4], mx[4] = {-INF, -INF, -INF, -INF};
auto check = [&](int p, int id) {
return p >= 0 && p < arr.size() && make_pair(arr[p].p, arr[p].q) == pos[id];
};
for(int i = 0; i < 4; i++)
it[i] = lower_bound(arr.begin(), arr.end(), dat(pos[i].first, pos[i].second, -INF, -INF)) - arr.begin();
auto update = [&](int val) {
for(int i = 0; i < 4; i++) {
while(check(it[i], i) && arr[it[i]].l <= val) {
mx[i] = max(mx[i], arr[it[i]].r);
it[i]++;
}
}
};
int prv = -INF;
while(check(it[0], 0) || check(it[1], 1) || check(it[2], 2) || check(it[3], 3)) {
int l = INF;
for(int i = 0; i < 4; i++)
if(check(it[i], i))
l = min(l, arr[it[i]].l);
l = max(prv, l);
update(l);
int r = INF;
for(int i = 0; i < 4; i++)
r = min(r, mx[i]);
if(l <= r) {
ans += (r - l + 1);
prv = r + 1;
}
}
}
cout << ans << '\n';
}
Compilation message
2016_ho_t4.cpp: In function 'int main()':
2016_ho_t4.cpp:117:3: error: 'has' was not declared in this scope
117 | has.insert(res);
| ^~~
2016_ho_t4.cpp: In lambda function:
2016_ho_t4.cpp:140:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<dat>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
140 | return p >= 0 && p < arr.size() && make_pair(arr[p].p, arr[p].q) == pos[id];
| ~~^~~~~~~~~~~~
