USACO 2021 December Contest (Bronze)

USACO/2021.12-Bronze/1/1.cpp

@@ -0,0 +1,40 @@
+#include <iostream>
+#include <vector>
+
+using std::cin;
+using std::cout;
+using std::endl;
+
+int n;
+long long ans;
+char c;
+std::vector<int> g, h;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin >> n;
+    g.push_back(0);
+    h.push_back(0);
+    for (int i = 1; i <= n; i++) {
+        cin >> c;
+        if (c == 'G') {
+            g.push_back(i);
+        } else {
+            h.push_back(i);
+        }
+    }
+    g.push_back(n + 1);
+    h.push_back(n + 1);
+    for (int i = 1; i < h.size() - 1; i++) {
+        ans += 1ll * (h[i] - h[i - 1]) * (h[i + 1] - h[i]) - 3;
+        if (h[i] == h[i - 1] + 1) ans++;
+        if (h[i] == h[i + 1] - 1) ans++;
+    }
+    for (int i = 1; i < g.size() - 1; i++) {
+        ans += 1ll * (g[i] - g[i - 1]) * (g[i + 1] - g[i]) - 3;
+        if (g[i] == g[i - 1] + 1) ans++;
+        if (g[i] == g[i + 1] - 1) ans++;
+    }
+    cout << ans << endl;
+    return 0;
+}

USACO/2021.12-Bronze/2/2.cpp

@@ -0,0 +1,27 @@
+#include <iostream>
+
+using std::cin;
+using std::cout;
+using std::endl;
+
+int n, x, a[100005], b[100005], ans;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin >> n;
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+    }
+    for (int i = 1; i <= n; i++) {
+        cin >> x;
+        a[i] -= x;
+        if (a[i] < 0) {
+            b[i] = -a[i];
+            a[i] = 0;
+        }
+        if (a[i] > a[i - 1]) ans += a[i] - a[i - 1];
+        if (b[i] > b[i - 1]) ans += b[i] - b[i - 1];
+    }
+    cout << ans << endl;
+    return 0;
+}

USACO/2021.12-Bronze/3/3.cpp

@@ -0,0 +1,34 @@
+#include <iostream>
+#include <string>
+
+using std::cin;
+using std::cout;
+using std::endl;
+
+int t, n, k, ans;
+std::string g[55];
+
+void dfs(int x, int y, int cnt, int from) {
+    if (x < 0 || x >= n || y < 0 || y > n || cnt > k || g[x][y] == 'H') return;
+    if (x == n - 1 && y == n - 1) {
+        ans++;
+        return;
+    }
+    dfs(x + 1, y, cnt + (from == 2), 1);
+    dfs(x, y + 1, cnt + (from == 1), 2);
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin >> t;
+    while (t--) {
+        ans = 0;
+        cin >> n >> k;
+        for (int i = 0; i < n; i++) {
+            cin >> g[i];
+        }
+        dfs(0, 0, 0, 0);
+        cout << ans << endl;
+    }
+    return 0;
+}