第三题 public class test8 { public sta

2018-03-25 12:07 北京电影学院 Java

关注

第三题 public class test8 { public static void main(String[] args) { // TODO Auto-generated method stub Scanner scanner = new Scanner(System.in); int n = scanner.nextInt(); int[] array = new int[n]; for (int i = 0; i < n; i++) { array[i] = scanner.nextInt(); } List<List<Integer>> list = new ArrayList<>(); backtrack(list, new ArrayList<>(), array); for (List<Integer> list2 : list) { for (Integer integer: list2) { System.out.print(integer); } System.out.println(); } } public static void backtrack(List<List<Integer>> list, List<Integer> templist, int[] nums){ if (templist.size() == nums.length) { list.add(new ArrayList<>(templist));// 符合条件的加入进去 } else { for (int i = 0; i < nums.length; i++) { if (templist.contains(nums[i])){ // 这个判断是否包含重复也是及其精妙啊 continue; } templist.add(nums[i]); backtrack(list, templist, nums); templist.remove(templist.size() - 1); } } } } 第一题 public class test6 { public static void main(String[] args) { // TODO Auto-generated method stub Scanner scanner = new Scanner(System.in); String string = scanner.nextLine(); Set<String> set = new HashSet<>(); char[] chars = string.toCharArray(); int l = 0; int r = 0; for (int i = 0; i < string.length(); i++) { while (chars[r] < '0' || chars[r] > '9') { l++; r++; } StringBuilder stringBuilder = new StringBuilder(); while (chars[r] >= '0' && chars[r] <= '9') { stringBuilder.append(chars[r++]); if (r >= string.length()) { break; } } set.add(stringBuilder.toString()); i = r - 1; } int res = Integer.MIN_VALUE; for (String s : set) { res = Math.max(res, Integer.valueOf(s)); } System.out.println(res); } } 第二题，有点bug，只通过了 16%，没时间调了， public class test7 { public static void main(String[] args) { // TODO Auto-generated method stub Scanner scanner = new Scanner(System.in); int n = scanner.nextInt(); int[] array = new int[n]; for (int i = 0; i < n; i++) { array[i] = scanner.nextInt(); } if (array.length == 1) { System.out.println(array[0]); } else if (array.length == 2) { System.out.println(array[0] + "," + array[1]); } else { StringBuilder stringBuilder = new StringBuilder(); for (int i =0; i < array.length; i++) { StringBuilder temp = new StringBuilder(); int start = array[i]; temp.append(start + ""); if ((start + 1) < array.length && array[start + 1] - array[start] > 1) { stringBuilder.append(array[start] + ","); } else { int temprr = Backing(temp, array, start + 1); if (temprr >= 3) { String ssss = array[start] + "-" + array[start + temprr - 1] + ","; stringBuilder.append(ssss); } else { stringBuilder.append(array[start] + ","); } } } System.out.println(stringBuilder.toString()); } } public static int Backing(StringBuilder stringBuilder, int[] array, int start) { stringBuilder.append(array[start] + ""); if ((start + 1) < array.length && array[start + 1] - array[start] > 1) { return stringBuilder.length(); } return Backing(stringBuilder, array, start + 1); } }

牛客热帖