PA2-zkouska/lock.cpp

72 lines
1.6 KiB
C++

#include <vector>
#include <unordered_set>
#include <string>
#include <queue>
#include <iostream>
class Solution {
public:
union u {
public:
char c[4];
int i;
};
int openLock(std::vector<std::string>& deadends, std::string target) {
std::unordered_set<int> e;
std::queue<std::pair<u,int>> q;
u t;
u b;
b.i = 0;
for (int i = 0; i < 4; ++i) {
t.c[i] = static_cast<char>(target[i] - '0');
}
for (const auto& i : deadends) {
if (target == i || i == "0000") return -1;
u tmp;
for (int j = 0; j < 4; ++j) {
tmp.c[j] = static_cast<char>(i[j] - '0');
}
e.insert(tmp.i);
}
e.insert(0);
q.emplace(b,0);
while(q.size()) {
auto i = q.front();
q.pop();
if (i.first.i == t.i) return i.second;
for (int j = 0; j < 4; ++j) {
u w = i.first;
++w.c[j] %= 10;
auto it = e.emplace(w.i);
if (it.second) {
q.emplace(w, i.second + 1);
}
}
for (int j = 0; j < 4; ++j) {
u w = i.first;
if (!w.c[j]--) w.c[j] = 9;
auto it = e.emplace(w.i);
if (it.second) {
q.emplace(w, i.second + 1);
}
}
}
return -1;
}
};
int main() {
Solution s;
std::vector<std::string> v = {"8888"};
std::cout << s.openLock(v, "0009");
return 0;
}