1. 合唱队
题目 大意： 将数组分成若干个数组 ，子数组内部从小到大排序，使所有子数组整体按非递减顺序，求子数组最大数量；
输入
4
2 1 3 2
输出
2
输入
10
69 230 77 650 440 270 750 760 990 880
输出
6
代码：
import java.util.Scanner;
public class B9 {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
sc.nextLine();
String[] str = sc.nextLine().split(" ");
long[] val = new long[n];
for (int i = 0; i < n; i++) {
val[i] = Long.valueOf(str[i]);
}
int[] positions = new int[n];
int count = 0;
int index = 0;
while(index< n-1){
long min = Long.MAX_VALUE;
int i = index;
for (; i < n; i++) {
if(min> val[i]){
min = val[i];
positions[count]= i;
}
}
if(positions[count]==index){
index = index+1;
}else{
index = positions[count]+1;
}
count++;
}
System.out.println(count);
}
}
2. 考场安排
考场不允许两个很熟的异性朋友存在，学习希望通过搬出一部分学生来解决问题，问
第二题，输入n和m，然后输入的是m行对应朋友关系，希望一个教师中容下的学生尽可能多，搬出学生尽可能少，求搬出人数最少且字典序最小的方案
输入：
2 2
1 3
1 4
输出：
1
1
import java.util.Arrays;
import java.util.LinkedList;
import java.util.Scanner;
public class B8 {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int m = sc.nextInt();
sc.nextLine();
int len = 2*n +1;
int[] du = new int[len];
int count = m;
boolean[][] relation = new boolean[len][len];
for (int i = 0; i < m; i++) {
String[] str = sc.nextLine().split(" ");
int val1 = Integer.valueOf(str[0]);
int val2 = Integer.valueOf(str[1]);
int boy = Math.min(val1, val2);
int girl = Math.max(val1, val2);
relation[boy][girl] = true;
du[boy]++;
du[girl]++;
}
LinkedList<Integer> result = new LinkedList<>();
while(count>0){
int[] tempdu = Arrays.copyOf(du,len);
Arrays.sort(tempdu);
int maxdu = tempdu[len-1];
if(maxdu==0){
break;
}
for (int i = 1; i < len; i++) {
if(du[i]==maxdu){
for (int j = n; j < len; j++) {
if(relation[i][j]){
relation[i][j]=false;
du[i]--;
du[j]--;
count--;
}
}
result.add(i);
}
}
}
int alen = result.size();
System.out.println(alen);
for (int i = 0; i < alen; i++) {
System.out.print(result.get(i));
if(i==alen-1){
System.out.print(" ");
}
}
}
}