Loop structure programming 2

The first 1 Turn off ：C loop - For the average score

• Task description
• Related knowledge
  • while sentence
  • for sentence
• Programming requirements
• Test instructions

---

Task description

Our mission ： Write a program , Enter the number of students and each person's grade , Calculate average .
###### Be careful ： When the number of students entered is less than or equal to 0 when , The average score is output 0 branch ！
for example ：

Related knowledge

In programming , We often encounter situations where we need to run a statement or a piece of code several times , If there is no circular statement , To be prepared item by item , It will lead to the complexity and redundancy of the program .

C Available in while、for、do-while And other commonly used loop functions to repeat statements or code blocks , So as to save a lot of repetitive work , Make the code simple and clear .

while sentence

Basic grammar ： be based on while The basic syntax for implementing a loop is as follows ：

1. while( Boolean value ){
2. Statements or blocks of code that require a loop
3. }

• If the Boolean value in brackets is true , This goes into the loop , Until the Boolean becomes false , Then we will launch the cycle , After the execution continues, the code .
• If the Boolean value in brackets is false , Then it will not enter the cycle directly , After continuing to execute the loop code block, the code .

Application example ：

1. // Cyclic output is required 3 Time 6
2. int n = 3;
3. while(n--){
4. printf("6");
5. }

for sentence

Basic grammar ： be based on for The basic syntax for implementing a loop is as follows ：

1. for(1. Assignment statement or omit ;2. Judge or omit ;3. Execute a statement or omit ){
2. Statements or code blocks that need to be looped
3. }

• among 1 Location , It's an assignment statement , In circulation Start Do it once before , Then do not execute .
• among 2 Position is a judgment statement , Every time Start the cycle when （ Including the first time ） Will go through the judgment statement first
  • If this is true , Then enter the cycle , Execute loop statements or code blocks .
  • If this is false , Then it does not enter the cycle , Code after execution .
• among 3 Position is an operation statement , Every time After execution A loop , Will execute the code here once .

Application example ：

1. // Output is also required 3 individual 6
2. int i;
3. for(i=0;i<3;i++){
4. printf("6");
5. }

Programming requirements

The programming task of this pass is to complete the code fragment on the right Begin to End The code in the middle , The specific requirements are as follows ：
Programming to realize ： Write a program , Enter the number of students and each person's grade , Calculate average .
###### Be careful ： When the number of students entered is less than or equal to 0 when , The average score is output 0 branch ！
for example ：

-

The code framework of the code file involved in this level is as follows ：

1. #include <stdio.h>
2. // Definition main function
3. int main()
4. {
5. // Please add code here
6. /********** Begin *********/
7. /********** End **********/
8. return 0;
9. }

Test instructions

Here is a sample test ：

Input ：3 90 70 80
Output ：the number of students:the scores:average=80.00
Input ：-1
Output ：the number of students:the scores:average=0.00
Input ：4 78.5 26 73.6 90.1

#include<stdio.h>
 int main()
{
	int n,i;
	float score,sum=0,average;
	scanf("%d",&n);
	for(i=1;i<=n;i++)
	{
		scanf("%f",&score);
		sum+=score;
	}
	average=(n<=0?0:sum/n);
	printf("the number of students:the scores:average=%.2f",average);
}

The first 2 Turn off ：C loop - Find the product of your numbers

• Task description
• Related knowledge
  • while sentence
  • for sentence
• Programming requirements
• Test instructions

---

Task description

Our mission ： Calculate a positive integer num The product of the numbers on .
for example ：

Input ：2583 after ----(2x5x8x3) Output ：240

Input ：102 after ----(1x0x2) Output ：0

Input ：136 after ----(1x3x6) Output ：18

Related knowledge

In programming , We often encounter situations where we need to run a statement or a piece of code several times , If there is no circular statement , To be prepared item by item , It will lead to the complexity and redundancy of the program .

C Available in while、for、do-while And other commonly used loop functions to repeat statements or code blocks , So as to save a lot of repetitive work , Make the code simple and clear .

while sentence

Basic grammar ： be based on while The basic syntax for implementing a loop is as follows ：

1. while( Boolean value ){
2. Statements or blocks of code that require a loop
3. }

• If the Boolean value in brackets is true , This goes into the loop , Until the Boolean becomes false , Then we will launch the cycle , After the execution continues, the code .
• If the Boolean value in brackets is false , Then it will not enter the cycle directly , After continuing to execute the loop code block, the code .

Application example ：

1. // Cyclic output is required 3 Time 6
2. int n = 3;
3. while(n--){
4. printf("6");
5. }

for sentence

Basic grammar ： be based on for The basic syntax for implementing a loop is as follows ：

1. for(1. Assignment statement or omit ;2. Judge or omit ;3. Execute a statement or omit ){
2. Statements or code blocks that need to be looped
3. }

• among 1 Location , It's an assignment statement , In circulation Start Do it once before , Then do not execute .
• among 2 Position is a judgment statement , Every time Start the cycle when （ Including the first time ） Will go through the judgment statement first
  • If this is true , Then enter the cycle , Execute loop statements or code blocks .
  • If this is false , Then it does not enter the cycle , Code after execution .
• among 3 Position is an operation statement , Every time After execution A loop , Will execute the code here once .

Application example ：

1. // Output is also required 3 individual 6
2. int i;
3. for(i=0;i<3;i++){
4. printf("6");
5. }

Programming requirements

The programming task of this pass is to complete the code fragment on the right Begin to End The code in the middle , The specific requirements are as follows ：
Calculate a positive integer num The product of the numbers on .
for example ：

Input ：2583 after ----(258*3) Output ：240

Input ：102 after ----(102) Output ：0

Input ：136 after ----(136) Output ：18

The code framework of the code file involved in this level is as follows ：

1. #include <stdio.h>
2. // Definition main function
3. int main()
4. {
5. // Please add code here
6. /********** Begin *********/
7. /********** End **********/
8. return 0;
9. }

Test instructions

Here is a sample test ：

Input ：120
Output ：0
Input ：314
Output ：12
Input ：1952
Output ：90

#include<stdio.h>
int main()
{
	int i,a,b,c=1;
	scanf("%d",&a);
    if(a%10==0)
    {
        printf("0\n");
    }
	else
    {
    while(a%10!=0)
		{i=(int)a/10;
		b=a%10;
		a=i;
		c=c*b;}
    printf("%d\n",c);
    }
       return 0;
}

The first 3 Turn off ：C loop - Find the sum of factorials

• Task description
• Related knowledge
  • while sentence
  • for sentence
• Programming requirements
• Test instructions

---

Task description

Our mission ： Write a program , Any input n, seek S=1!+2!+...+n!. Be careful ：n! Express n The factorial .0 The factorial of is equal to 1, The factorial of a negative number is equal to 0.
* Tips ：(n+1)!=n!(n+1)** for example ：
Input ：10
Output ：4037913

Input ：7
Output ：5913

Input ：-1
Output ：0

Related knowledge

In programming , We often encounter situations where we need to run a statement or a piece of code several times , If there is no circular statement , To be prepared item by item , It will lead to the complexity and redundancy of the program .

C Available in while、for、do-while And other commonly used loop functions to repeat statements or code blocks , So as to save a lot of repetitive work , Make the code simple and clear .

while sentence

Basic grammar ： be based on while The basic syntax for implementing a loop is as follows ：

1. while( Boolean value ){
2. Statements or blocks of code that require a loop
3. }

• If the Boolean value in brackets is true , This goes into the loop , Until the Boolean becomes false , Then we will launch the cycle , After the execution continues, the code .
• If the Boolean value in brackets is false , Then it will not enter the cycle directly , After continuing to execute the loop code block, the code .

Application example ：

1. // Cyclic output is required 3 Time 6
2. int n = 3;
3. while(n--){
4. printf("6");
5. }

for sentence

Basic grammar ： be based on for The basic syntax for implementing a loop is as follows ：

1. for(1. Assignment statement or omit ;2. Judge or omit ;3. Execute a statement or omit ){
2. Statements or code blocks that need to be looped
3. }

• among 1 Location , It's an assignment statement , In circulation Start Do it once before , Then do not execute .
• among 2 Position is a judgment statement , Every time Start the cycle when （ Including the first time ） Will go through the judgment statement first
  • If this is true , Then enter the cycle , Execute loop statements or code blocks .
  • If this is false , Then it does not enter the cycle , Code after execution .
• among 3 Position is an operation statement , Every time After execution A loop , Will execute the code here once .

Application example ：

1. // Output is also required 3 individual 6
2. int i;
3. for(i=0;i<3;i++){
4. printf("6");
5. }

Programming requirements

The programming task of this pass is to complete the code fragment on the right Begin to End The code in the middle , The specific requirements are as follows ：
Programming to realize ： Any input n, seek S=1!+2!+...+n!. ###### Be careful ：n! Express n The factorial .0 The factorial of is equal to 1, The factorial of a negative number is equal to 0.

The code framework of the code file involved in this level is as follows ：

1. #include <stdio.h>
2. // Definition main function
3. int main()
4. {
5. // Please add code here
6. /********** Begin *********/
7. /********** End **********/
8. return 0;
9. }

Test instructions

Here is a sample test ：

Input ：10
Output ：4037913
Input ：1
Output ：1
Input ：-5
Output ：0

#include <stdio.h>
int main()
{ int sum,item,i,j,n;
  scanf("%d",&n);
  sum=0;
  for(i=1;i<=n;i++)
   {item=1;
    for(j=1;j<=i;j++)
       item=item*j;
     sum=sum+item;
   }
      printf("%d",sum);
 
    
    return 0;
}

The first 4 Turn off ：C loop - Narcissistic number

• Task description
• Related knowledge
  • while sentence
  • for sentence
• Programming requirements
• Test instructions

---

Task description

Our mission ： Find all the daffodils .

Tips ： The so-called narcissus number refers to a three digit number , The cubic sum of its digits is equal to the number itself . such as 153 It's a narcissus number , because 153=1^3+5^3+3^3.

Be careful ： There is no need to enter a sentence , Due to site restrictions, input and output examples are required , But students can ignore the input part .
for example ：
370 It's a narcissus number , because 370 = 3^3 +7^3 + 0^3

Related knowledge

In programming , We often encounter situations where we need to run a statement or a piece of code several times , If there is no circular statement , To be prepared item by item , It will lead to the complexity and redundancy of the program .

C Available in while、for、do-while And other commonly used loop functions to repeat statements or code blocks , So as to save a lot of repetitive work , Make the code simple and clear .

while sentence

Basic grammar ： be based on while The basic syntax for implementing a loop is as follows ：

1. while( Boolean value ){
2. Statements or blocks of code that require a loop
3. }

• If the Boolean value in brackets is true , This goes into the loop , Until the Boolean becomes false , Then we will launch the cycle , After the execution continues, the code .
• If the Boolean value in brackets is false , Then it will not enter the cycle directly , After continuing to execute the loop code block, the code .

Application example ：

1. // Cyclic output is required 3 Time 6
2. int n = 3;
3. while(n--){
4. printf("6");
5. }

for sentence

Basic grammar ： be based on for The basic syntax for implementing a loop is as follows ：

1. for(1. Assignment statement or omit ;2. Judge or omit ;3. Execute a statement or omit ){
2. Statements or code blocks that need to be looped
3. }

• among 1 Location , It's an assignment statement , In circulation Start Do it once before , Then do not execute .
• among 2 Position is a judgment statement , Every time Start the cycle when （ Including the first time ） Will go through the judgment statement first
  • If this is true , Then enter the cycle , Execute loop statements or code blocks .
  • If this is false , Then it does not enter the cycle , Code after execution .
• among 3 Position is an operation statement , Every time After execution A loop , Will execute the code here once .

Application example ：

1. // Output is also required 3 individual 6
2. int i;
3. for(i=0;i<3;i++){
4. printf("6");
5. }

Programming requirements

The programming task of this pass is to complete the code fragment on the right Begin to End The code in the middle , The specific requirements are as follows ：
Find all the daffodils .
Tips ： The so-called narcissus number refers to a three digit number , The cubic sum of its digits is equal to the number itself . such as 153 It's a narcissus number , because 153=1^3+5^3+3^3.·
Be careful ： There is no need to enter a sentence , Due to site restrictions, input and output examples are required , But students can ignore the input part .
for example ：
370 It's a narcissus number , because 370 = 3^3 +7^3 + 0^3
The code framework of the code file involved in this level is as follows ：

1. #include <stdio.h>
2. // Definition main function
3. int main()
4. {
5. // Please add code here
6. /********** Begin *********/
7. /********** End **********/
8. return 0;
9. }

Test instructions

Here is a sample test ：

Input ： 1

#include <stdio.h>
 
int main()
{
   int i,a,b,c;
   for(i=100;i<1000;i++)
   {
      a=i/100;// Hundred bit 
      b=i%100/10;// ten     Or you could write it as b=i/10%10;
      c=i%10;// bits 
      if(a*a*a+b*b*b+c*c*c==i)
      {
          printf("%d ",i);
      }
   }
 
    return 0;
}

The first 5 Turn off ：C loop - Find the perfect number

• Task description
• Related knowledge （ A little ）
• Programming requirements
• Test instructions

---

Task description

Our mission ： If a number is exactly equal to the sum of its factors , This number is called " Complete ". for example ,6 The factor is 1、2、3, and 6=1+2+3, therefore 6 yes " Complete ". Program to find out 1000 All the completions in .

Related knowledge （ A little ）

Programming requirements

According to the prompt , On the right editor Begin-End Add the code , And complete the task as required .
Input
1000

Output
Program to find out 1000 All the completions in , Each of them takes up one line .

Test instructions

Input ：1000
Output ：
6
28
496

#include<stdio.h>
int main(void)
{  
    /*********Begin*********/
	int i, j;
    for(i = 2; i <= 1000; i++) {
        int sum = 0;
        for(j = 1; j <= i / 2; j++)
            if(i % j == 0) sum += j;
        if(sum == i)
            printf("%d\n", sum);
    }
	  
	/*********End**********/ 
    return 0;
}

The first 6 Turn off ： Sum fractions

• Task description
• Related knowledge （ A little ）
• Programming requirements
• Test instructions

---

Task description

Our mission ： Write programs to calculate 1 - 1/2 + 1/3 - 1/4 + ..... +1/99 - 1/100 Value , And show it ( Keep the result to three decimal places ).

Related knowledge （ A little ）

Programming requirements

According to the prompt , On the right editor Begin-End Add the code , Write programs to calculate 1 - 1/2 + 1/3 - 1/4 + ..... +1/99 - 1/100 Value , And show it ( Keep the result to three decimal places ).

Test instructions

The platform will test your code , If it is the same as the expected output , Customs clearance .

---

Start your mission , wish you success ！

#include<stdio.h>
	int main(void)
	{  
	  /*********Begin*********/
	  int s;
     double sum,t,d;
      sum=1.0;
      d=2.0;
      s=1;
  
     while(d <= 100)
     {
         s=(-1)*s;
         t=s*(1/d);
         sum = sum + t;
         d=d+1;
     }
     printf("%.3f\n",sum);
	  
	  /*********End**********/ 
       return 0;
	}