complete jungol//2194.cpp and fix it

storage/jungol/cpp/completed/4520.cpp

@@ -0,0 +1,50 @@
+#include <algorithm>
+#include <cstdint>
+#include <iostream>
+#include <vector>
+
+#define let auto
+#define fn auto
+typedef size_t usize;
+using namespace std;
+
+fn fastio() {
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+}
+
+fn main() -> int {
+    usize n, k;
+    cin >> n >> k;
+    let line = vector<char>(n);
+    let valid = vector<bool>(n, false);
+    for (usize i = 0; i < n; i++) {
+        char t;
+        cin >> t;
+
+        line[i] = t;
+        if (t == 'H') {
+            valid[i] = true;
+        }
+    }
+
+    // left assoc
+
+    let count = 0;
+    for (usize i = 0; i < n; i++) {
+        if (line[i] == 'P') {
+            let left = i >= k ? i - k : 0;
+            let right = i + k >= n ? n - 1 : i + k;
+
+            for (usize j = left; j <= right; j++) {
+                if (valid[j]) {
+                    count += 1;
+                    valid[j] = false;
+                    break;
+                }
+            }
+        }
+    }
+
+    cout << count << endl;
+}