/** * Reads a sequence of transactions from standard input; takes a command-line integer M; prints to * standard output the M largest transactions in descending order. */ public static void main(String[] args) { int M = Integer.parseInt(args[0]); MinPQ<Transaction> pq = new MinPQ<Transaction>(M + 1); while (StdIn.hasNextLine()) { // Create an entry from the next line and put on the PQ. String line = StdIn.readLine(); Transaction transaction = new Transaction(line); pq.insert(transaction); // remove minimum if M+1 entries on the PQ if (pq.size() > M) pq.delMin(); } // top M entries are on the PQ // print entries on PQ in reverse order Stack<Transaction> stack = new Stack<Transaction>(); for (Transaction transaction : pq) stack.push(transaction); for (Transaction transaction : stack) StdOut.println(transaction); }
private void dfs(Digraph G, int v) { marked[v] = true; preorder[v] = pre++; stack1.push(v); stack2.push(v); for (int w : G.adj(v)) { if (!marked[w]) dfs(G, w); else if (id[w] == -1) { while (preorder[stack2.peek()] > preorder[w]) stack2.pop(); } } // found strong component containing v if (stack2.peek() == v) { stack2.pop(); int w; do { w = stack1.pop(); id[w] = count; } while (w != v); count++; } }
/** * Returns the vertices in reverse postorder. * * @return the vertices in reverse postorder, as an iterable of vertices */ public Iterable<Integer> reversePost() { Stack<Integer> reverse = new Stack<Integer>(); for (int v : postorder) reverse.push(v); return reverse; }