# 1. Seek 1! +2! +3! +···+30! Harmony, define a method

public class test1 { 
 Public Static void main (string [] args) { 
 // 1. Seek 1! +2! +3! +···+30! Harmony, define a method 
 Long Sum = 0; 
 for (int i = 1; i <= 30; i ++) { 
 SUM+= getjiecheng (i); 
 } 
 System.out.println ("Sum ="+Sum); 
 } 
 
 public static int getjiecheng (int a) {{ 
 int jiecheng = 1; 
 for (int i = 1; i <= a; i ++) { 
 jiecheng*= i; 
 } 
 Return jiecheng; 
 } 
 
 }

# 2. Define the number of strange numbers in the array and the number of the number of strange numbers in the array

public class test2 {{ 
 Public Static void main (string [] args) { 
 // 2. Define the number of unilateral array, find the number of odd numbers in the array and the number of even numbers 
 int [] arr = {1,3,5,6,2,56,5}; 
 
 // The number of even numbers 
 int count = 0; 
 for (int i = 0; I <arr.Length; i ++) { 
 if (ARR [i]%2 == 0) {{ 
 Count ++; 
 } 
 } 
 System.out.println ("Evencount ="+Count); 
 System.out.println ("Oddcount ="+(Arr.Length-Count)); 
 } 
 }

# 3. ODARR = {1,3,5,0,0,6,0,5,4,7,7,0,5} Requires the item of 0 in the array Stay in a new array

public class test3 {{ 
 Public Static void main (string [] args) { 
 //3.ODDARR= {1,3,5,0,6,0,5,4,7,0,5} 
 // Requires to remove the item of 0 in the array, and save the item that is not 0 into a new array 
 int [] oddarr = {1,3,5,0,0,6,0,5,4,7,0,5}; 
 
 // Calculate the number of 0 in the array, prepare for the new array 
 int count = 0; 
 for (int i = 0; I <Oddarr.Length; I ++) { 
 if (ODDARR [i] == 0) {{ 
 Count ++; 
 } 
 } 
 
 // Create a new array 
 int count1 = 0; 
 int [] newsr = new int 
 for (int i = 0; I <Oddarr.Length; I ++) { 
 if (ODDARR [i]! = 0) { 
 count1 ++; 
 newarr [count1-1] = Oddarr [i]; 
 } 
 } 
 for (int m: newarr) { 
 System.out.print (m+""); 
 } 
 
 } 
 }

# 4. There are 30 0 0

Number between_{9, statistics 0}9 The number of times each number appears in each number

Import java.util.arrays; 
 public class test4 {{ 
 Public Static void main (string [] args) { 
 // There are 30 numbers between 0 ~ 9, and the number of times each number appears in each number 0-9 
 // int random = (int) (math.random ()*10); 
 int [] arr = new int [30]; 
 
 // Assign to the array 
 for (int i = 0; I <arr.Length; i ++) { 
 arr [i] = (int) (math.random ()*10); 
 } 
 
 // Statistics the number of times of each number 
 int [] count = new int [10]; 
 
 for (int i = 0; i <count.length; i ++) { 
 for (int j = 0; j <arr.Length; j ++) { 
 if (arr [j] == i) { 
 count [i] ++; 
 } 
 } 
 } 
 
 System.out.println ("Value in the original array:"+Arrays.tostring (ARR)); 
 System.out.println ("The number of times appeared from 0 ~ 9:"+Arrays.tostring (Count)); 
 } 
 }

# 5. Add a number to the sorted number and place the number in a suitable position

Import java.util.arrays; 
 public class test5 { 
 Public Static void main (string [] args) { 
 // 5. Add a number to the sorted number, put the number in a suitable position 
 int [] arr = new int [20]; 
 
 // Add numbers to array 
 for (int i = 0; I <arr.Length; i ++) { 
 arr [i] = (int) (math.random ()*30) +1; 
 } 
 System.out.println ("Original array:"+Arrays.tostring (ARR)); 
 // Sort for arrays 
 // Select sorting 
 for (int i = 0; I <arr.Length-; i ++) { 
 int index = i; 
 for (int j = i+1; j <arr.length-1; j ++) { 
 if (ARR [Index]> Arr [J]) {{ 
 Index = j; 
 } 
 } 
 
 // Implement exchange 
 int Temp = Arr [i]; 
 arr [i] = Arr [Index]; 
 arr [index] = temp; 
 } 
 System.out.println ("Organic array:+Arrays.Tostring (ARR)); 
 
 // Define a number to be put in 
 int a = 5; 
 
 // First get the position to get the number first 
 int count = 0; 
 for (int i = 0; I <arr.Length; i ++) { 
 if (ARR [i] <a) { 
 Count ++; 
 } 
 } 
 
 // Put the new number in the array 
 int [] newsr = new int [21]; 
 for (int i = 0; I <newarr.Length; i ++) { 
 if (i <= count) { 
 newarr [i] = arr [i]; 
 } else if (i == Count+1) {{ 
 newarr [i] = a; 
 } else { 
 newarr [i] = Arr [i-1]; 
 } 
 } 
 System.out.println ("New array after inserting numbers:"+Arrays.tostring (newarr)); 
 } 
 }