Solved A and B in the last Div2

1 files changed, 166 insertions, 0 deletions

diff --git a/codeforces/TheWayToHome/] b/codeforces/TheWayToHome/]
new file mode 100644
index 0000000..dbdfb72
--- /dev/null
+++ b/codeforces/TheWayToHome/]
@@ -0,0 +1,166 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpi = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x)                                                         \
+  sort(all((x)));                                                              \
+  (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b)-1) / (b)
+
+const int MOD = (int)1e9 + 7;
+const db PI = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const pair<K, V> &p);
+template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec);
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const map<K, V> &m);
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const unordered_map<K, V> &m);
+template <typename T> ostream &operator<<(ostream &os, const set<T> &s);
+template <typename T>
+ostream &operator<<(ostream &os, const unordered_set<T> &s);
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const pair<K, V> &p) {
+  os << "(" << p.first << ", " << p.second << ")";
+  return os;
+}
+
+template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) {
+  os << "{";
+  for (size_t i = 0; i < vec.size(); ++i) {
+    if (i > 0)
+      os << ", ";
+    os << vec[i];
+  }
+  os << "}";
+  return os;
+}
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const map<K, V> &m) {
+  os << "{";
+  for (const auto &p : m) {
+    os << p.first << ": " << p.second << ", ";
+  }
+  os << "}";
+  return os;
+}
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const unordered_map<K, V> &m) {
+  os << "{";
+  for (const auto &p : m) {
+    os << p.first << ": " << p.second << ", ";
+  }
+  os << "}";
+  return os;
+}
+
+template <typename T> ostream &operator<<(ostream &os, const set<T> &s) {
+  int i = 0;
+  os << "{";
+  for (const auto &e : s) {
+    if (i > 0)
+      os << ", ";
+    os << e;
+    i++;
+  }
+  os << "}";
+  return os;
+}
+
+template <typename T>
+ostream &operator<<(ostream &os, const unordered_set<T> &s) {
+  int i = 0;
+  os << "{";
+  for (const auto &e : s) {
+    if (i > 0)
+      os << ", ";
+    os << e;
+    i++;
+  }
+  os << "}";
+  return os;
+}
+
+void dbg() { cerr << "\n"; }
+
+template <typename T, typename... TS> void dbg(T val, TS... vals) {
+  cerr << val << " ";
+  dbg(vals...);
+}
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+void solve() {
+  int n, k;
+  cin >> n >> k;
+  string s;
+  cin >> s;
+  int cur = 0;
+  int ans = 0;
+  if (k == 1) {
+    for (int i = 0; i < n; i++) {
+      while (s[i] == 1) {
+        ans++;
+        i++;
+      }
+      if (ans == n - 1) {
+        cout << ans << '\n';
+      } else {
+        cout << -1 << '\n';
+      }
+      return;
+    }
+  }
+  while (true) {
+    int tmp = cur + 1;
+    bool ok = false;
+    for (int j = tmp + 1; j < min(n, tmp + k); j++) {
+      dbg(j);
+      if (s[j] == '1') {
+        ok = true;
+        cur = j;
+      }
+    }
+    if (!ok) {
+      cout << -1;
+      return;
+    }
+    ans++;
+    if (cur + 1 == n) {
+      break;
+    }
+  }
+  cout << ans << '\n';
+}
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  solve();
+}