#include <iostream> #include <vector> #include <string> #include <set> #include <climits> using namespace std; #define DEBUG false #define log if (DEBUG) cerr typedef long long ll; typedef unsigned long long ull; const ll INF_LL = 9223372036854775807LL; static vector<ll> balances; static vector<int> automat; static int n, m; static void readData() { int i; string program; cin >> n; balances.resize(n); for (auto& a : balances) { cin >> a; } cin >> m >> program; for (i = 0; i < m; i ++) { automat.push_back(program[i] == 'W'? +1 : -1); } } static ll solveForBoy(int cashIdx) { vector<ll> deltas; ll result; int autoIdx; set<int> visitedAutos; ll value; ll minDelta; ll cycleValue; ll balance = balances[cashIdx]; autoIdx = cashIdx % m; value = 0; minDelta = 55; log << "Boy " << cashIdx << endl; while (true) { visitedAutos.insert(autoIdx); value += automat[autoIdx]; deltas.push_back(value); minDelta = min(value, minDelta); autoIdx = (autoIdx + n) % m; if (visitedAutos.find(autoIdx) != visitedAutos.end()) { break; } } cycleValue = value; if (DEBUG) { log << "ba: " << balance << ", cv: " << cycleValue << ", md: " << minDelta << endl; for (auto delta : deltas) log << delta << ","; log << endl; } if (cycleValue >= 0 && balance + minDelta > 0) { return -1; } ll nc = 0; if (balance + minDelta > 0) { nc = (balance + minDelta) / (-cycleValue); if ((balance + minDelta) % (-cycleValue) > 0) { nc ++; } } result = nc * deltas.size(); value = balance + cycleValue * nc; for (ll delta : deltas) { result ++; if (value + delta <= 0) { break; } } log << "result: " << result << endl; return result; } static void solveBetter() { ll result = INF_LL; for (int i = 0; i < n; i++) { ll boyResult = solveForBoy(i); if (boyResult > 0) { boyResult = (boyResult-1) * n + i + 1; result = min(result, boyResult); } } if (result == INF_LL) { cout << -1; } else { cout << result; } } int main() { readData(); solveBetter(); return 0; }
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 | #include <iostream> #include <vector> #include <string> #include <set> #include <climits> using namespace std; #define DEBUG false #define log if (DEBUG) cerr typedef long long ll; typedef unsigned long long ull; const ll INF_LL = 9223372036854775807LL; static vector<ll> balances; static vector<int> automat; static int n, m; static void readData() { int i; string program; cin >> n; balances.resize(n); for (auto& a : balances) { cin >> a; } cin >> m >> program; for (i = 0; i < m; i ++) { automat.push_back(program[i] == 'W'? +1 : -1); } } static ll solveForBoy(int cashIdx) { vector<ll> deltas; ll result; int autoIdx; set<int> visitedAutos; ll value; ll minDelta; ll cycleValue; ll balance = balances[cashIdx]; autoIdx = cashIdx % m; value = 0; minDelta = 55; log << "Boy " << cashIdx << endl; while (true) { visitedAutos.insert(autoIdx); value += automat[autoIdx]; deltas.push_back(value); minDelta = min(value, minDelta); autoIdx = (autoIdx + n) % m; if (visitedAutos.find(autoIdx) != visitedAutos.end()) { break; } } cycleValue = value; if (DEBUG) { log << "ba: " << balance << ", cv: " << cycleValue << ", md: " << minDelta << endl; for (auto delta : deltas) log << delta << ","; log << endl; } if (cycleValue >= 0 && balance + minDelta > 0) { return -1; } ll nc = 0; if (balance + minDelta > 0) { nc = (balance + minDelta) / (-cycleValue); if ((balance + minDelta) % (-cycleValue) > 0) { nc ++; } } result = nc * deltas.size(); value = balance + cycleValue * nc; for (ll delta : deltas) { result ++; if (value + delta <= 0) { break; } } log << "result: " << result << endl; return result; } static void solveBetter() { ll result = INF_LL; for (int i = 0; i < n; i++) { ll boyResult = solveForBoy(i); if (boyResult > 0) { boyResult = (boyResult-1) * n + i + 1; result = min(result, boyResult); } } if (result == INF_LL) { cout << -1; } else { cout << result; } } int main() { readData(); solveBetter(); return 0; } |