戳印序列

/*
 * 使用Java Stream的题解
 * 1. 与Java的解法类似，但是使用Stream来简化一些操作。
 */
import java.util.*;
import java.util.stream.*;

public class SolutionStream {
    public int[] movesToStamp(String stamp, String target) {
        char[] s = stamp.toCharArray();
        char[] t = target.toCharArray();
        int slen = s.length, tlen = t.length;
        List<Integer> result = new ArrayList<>();
        boolean[] visited = new boolean[tlen];
        int stars = 0;

        while (stars < tlen) {
            boolean doneReplace = false;
            for (int i = 0; i <= tlen - slen; i++) {
                if (!visited[i] && canReplace(t, i, s)) {
                    stars = doReplace(t, i, slen, stars);
                    doneReplace = true;
                    visited[i] = true;
                    result.add(i);
                    if (stars == tlen) {
                        break;
                    }
                }
            }
            if (!doneReplace) {
                return new int[0];
            }
        }

        Collections.reverse(result);
        return result.stream().mapToInt(i -> i).toArray();
    }

    private boolean canReplace(char[] t, int p, char[] s) {
        return IntStream.range(0, s.length).allMatch(i -> t[p + i] == '*' || t[p + i] == s[i]);
    }

    private int doReplace(char[] t, int p, int len, int stars) {
        stars += (int) IntStream.range(0, len).filter(i -> t[p + i] != '*').peek(i -> t[p + i] = '*').count();
        return stars;
    }
}