#include <algorithm> #include <cstdio> #include <deque> #include <limits> #include <vector> using namespace std; typedef long long i64; int gcd(int x, int y) { while (y != 0) { int z = x%y; x = y; y = z; } return x; } struct S { S(const vector<int>& t); inline int get(int i, int j); vector<int> sum_; }; S::S(const vector<int>& t) : sum_(t.size()+1) { for (int i=1; i<=(int)t.size(); ++i) sum_[i] = sum_[i-1] + t[i-1]; } int S::get(int i, int j) { if (j < (int)sum_.size()-1) return sum_[j+1] - sum_[i]; else return sum_.back() - sum_[i] + sum_[j-((int)sum_.size()-1)+1]; } struct Problem { Problem(int n) : n_(n), m_(-1), g_(-1), a_(n) {} void setM(int m); i64 solve(); i64 solveCycle(int r); vector<int> getCycleBs(int r); vector<int> getCycleIxs(int r); int n_,m_,g_; vector<int> a_,b_; }; void Problem::setM(int m) { m_ = m; g_ = gcd(n_,m); b_.resize(m); } i64 Problem::solve() { i64 result = numeric_limits<i64>::max(); for (int i=0; i<g_; ++i) result = min(result, solveCycle(i)); return result == numeric_limits<i64>::max() ? -1 : result; } i64 Problem::solveCycle(int r) { vector<int> ccb = getCycleBs(r); S ccbs(ccb); vector<int> ccix = getCycleIxs(r); deque<int> st; pair<int,int> first0(numeric_limits<int>::max(), 0); int minScore = numeric_limits<int>::max(); for (int i=0; i<2*(m_/g_)-1; ++i) { if (i < m_/g_) { if (ccix[i] != -1) { while (!st.empty() && a_[ccix[st.back()]] + ccbs.get(st.back(),i-1) >= a_[ccix[i]]) st.pop_back(); st.push_back(i); } } else if (!st.empty() && st[0] == i-m_/g_) st.pop_front(); if (st.empty()) continue; int score = a_[ccix[st[0]]] + ccbs.get(st[0],i); minScore = min(minScore, score); if (score == 0) { first0 = min(first0, make_pair(i-st[0], ccix[st[0]])); st.pop_front(); } } if (minScore == 0) return (i64)first0.first*n_ + first0.second + 1; int bsum = ccbs.get(0,m_/g_-1); if (bsum >= 0) return numeric_limits<i64>::max(); bsum = -bsum; int k = (minScore+bsum-1)/bsum; for (int ix : ccix) if (ix != -1) a_[ix] -= k*bsum; return k*((i64)n_*(m_/g_)) + solveCycle(r); } vector<int> Problem::getCycleBs(int r) { vector<int> ccb(m_/g_); for (int& x : ccb) { x = b_[r]; r = (r+n_)%m_; } return ccb; } vector<int> Problem::getCycleIxs(int r) { vector<int> ccix(m_/g_, -1); for (int& x : ccix) { int q = r; while (q < n_) { if (x == -1 || (a_[q] < a_[x] || (a_[q] == a_[x] && q < x))) x = q; q += m_; } r = (r+n_)%m_; } return ccix; } int main() { int n; scanf("%d", &n); Problem p(n); for (int& x : p.a_) scanf("%d", &x); int m; scanf("%d", &m); p.setM(m); vector<char> tmp(m+1); scanf("%s", &tmp[0]); for (int i=0; i<m; ++i) { if (tmp[i] == 'W') p.b_[i] = 1; else p.b_[i] = -1; } printf("%lld\n", p.solve()); }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 | #include <algorithm> #include <cstdio> #include <deque> #include <limits> #include <vector> using namespace std; typedef long long i64; int gcd(int x, int y) { while (y != 0) { int z = x%y; x = y; y = z; } return x; } struct S { S(const vector<int>& t); inline int get(int i, int j); vector<int> sum_; }; S::S(const vector<int>& t) : sum_(t.size()+1) { for (int i=1; i<=(int)t.size(); ++i) sum_[i] = sum_[i-1] + t[i-1]; } int S::get(int i, int j) { if (j < (int)sum_.size()-1) return sum_[j+1] - sum_[i]; else return sum_.back() - sum_[i] + sum_[j-((int)sum_.size()-1)+1]; } struct Problem { Problem(int n) : n_(n), m_(-1), g_(-1), a_(n) {} void setM(int m); i64 solve(); i64 solveCycle(int r); vector<int> getCycleBs(int r); vector<int> getCycleIxs(int r); int n_,m_,g_; vector<int> a_,b_; }; void Problem::setM(int m) { m_ = m; g_ = gcd(n_,m); b_.resize(m); } i64 Problem::solve() { i64 result = numeric_limits<i64>::max(); for (int i=0; i<g_; ++i) result = min(result, solveCycle(i)); return result == numeric_limits<i64>::max() ? -1 : result; } i64 Problem::solveCycle(int r) { vector<int> ccb = getCycleBs(r); S ccbs(ccb); vector<int> ccix = getCycleIxs(r); deque<int> st; pair<int,int> first0(numeric_limits<int>::max(), 0); int minScore = numeric_limits<int>::max(); for (int i=0; i<2*(m_/g_)-1; ++i) { if (i < m_/g_) { if (ccix[i] != -1) { while (!st.empty() && a_[ccix[st.back()]] + ccbs.get(st.back(),i-1) >= a_[ccix[i]]) st.pop_back(); st.push_back(i); } } else if (!st.empty() && st[0] == i-m_/g_) st.pop_front(); if (st.empty()) continue; int score = a_[ccix[st[0]]] + ccbs.get(st[0],i); minScore = min(minScore, score); if (score == 0) { first0 = min(first0, make_pair(i-st[0], ccix[st[0]])); st.pop_front(); } } if (minScore == 0) return (i64)first0.first*n_ + first0.second + 1; int bsum = ccbs.get(0,m_/g_-1); if (bsum >= 0) return numeric_limits<i64>::max(); bsum = -bsum; int k = (minScore+bsum-1)/bsum; for (int ix : ccix) if (ix != -1) a_[ix] -= k*bsum; return k*((i64)n_*(m_/g_)) + solveCycle(r); } vector<int> Problem::getCycleBs(int r) { vector<int> ccb(m_/g_); for (int& x : ccb) { x = b_[r]; r = (r+n_)%m_; } return ccb; } vector<int> Problem::getCycleIxs(int r) { vector<int> ccix(m_/g_, -1); for (int& x : ccix) { int q = r; while (q < n_) { if (x == -1 || (a_[q] < a_[x] || (a_[q] == a_[x] && q < x))) x = q; q += m_; } r = (r+n_)%m_; } return ccix; } int main() { int n; scanf("%d", &n); Problem p(n); for (int& x : p.a_) scanf("%d", &x); int m; scanf("%d", &m); p.setM(m); vector<char> tmp(m+1); scanf("%s", &tmp[0]); for (int i=0; i<m; ++i) { if (tmp[i] == 'W') p.b_[i] = 1; else p.b_[i] = -1; } printf("%lld\n", p.solve()); } |