算法 囚犯幸存者

题目

主类

public static List<Prisoner> prisoners = new ArrayList<Prisoner>();
public static List<Prisoner> remainPrisoners = new ArrayList<Prisoner>();
public static Prisoner lastPrisoner = null;

public static void main(String[] args) {

    Random random = new Random();
    // 循环100次 生成100个囚犯
    for (int i = 0; i < 100; i++) {
        // 生成随机数
        Long code = (long) random.nextInt(200) + 1;
        if (existCode(code)) {
            i--;
            continue;
        }
        Prisoner prisoner = new Prisoner(code,(long) i + 1);
        prisoners.add(prisoner);
    }

    System.out.println("囚犯初始站位：") ;
    prisoners.forEach(System.out::println);

    // 深拷贝
    remainPrisoners = new ArrayList<>(prisoners);

    // 开始枪毙囚犯
    while (remainPrisoners.size() > 1) {
        killPrisoner();
    }

    lastPrisoner = remainPrisoners.get(0);
    System.out.println("最后一个囚犯编号：" + lastPrisoner.getCode());
    System.out.println("最后一个囚犯站位：" + lastPrisoner.getFirstPlace() );

}

public static boolean existCode(Long code) {
    // 判断囚犯编号是否存在 使用stream流
    return prisoners.stream().anyMatch(prisoner -> code.equals(prisoner.getCode()));
}

// 枪毙囚犯（枪毙奇数位置的囚犯）
public static void killPrisoner() {
    for (int i = remainPrisoners.size(); i > 0 ; i--) {
        if (i % 2 != 0) {
            System.out.println(i);
            remainPrisoners.remove(i-1);
        }
    }
    System.out.println("剩余囚犯：");
    remainPrisoners.forEach(System.out::println);
}

囚犯类

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Prisoner {
    private Long code;
    private Long firstPlace;
}