C Language Learning record "July"

1. The first applet: generate 20 random numbers between 30-70 and calculate their and, use the Arc4random () function, generate a random number between "X Y", Arc4random ()% (y-x+1) + x need to add a header file Stdlib.h

#include <stdio.h>

#include <stdlib.h>

int main ()

{

int a[20]={0};

int sum=0;

for (int i=0;i<20;i++) {

A[i]=arc4random ()%41+30;// to add stdlib header file, otherwise it will produce negative numbers

printf ("%d", a[i]);

Sum+=a[i];

}

printf ("\n%d", sum);

return 0;

}

2, the second small program: print 100 can not be divisible by 7, and does not contain 7 of the number

#include <stdio.h>

int main ()

{

int i;

for (i=1;i<=100;i++)

{

if (i%7==0 | | i%10==7| | i/10==7) {

Continue

}

printf ("%d", I);

}

return 0;

}

3, the third small program: shopping malls to buy things, more than 500, the portion of the beat 90 percent

#include <stdio.h>

int main ()

{

char c;

int money=0;

int realpay = 0;

do{

printf ("Please enter an amount:");

scanf ("%d", &money);

if (money>500)

{

Realpay= (money-500) *0.9+500;

}

else{

Realpay=money;

}

printf ("%d\n", Realpay);

printf ("Continue: y/n?");

GetChar ();

C=getchar ();

}while (c== ' Y ' | | c== ' y ');

return 0;

}

4, the fourth small program: Judge Leap year, four years a leap, a century does not leap, 400 years again leap

#include <stdio.h>

int main ()

{

char c;

int year=0;

do{

scanf ("%d", &year);

if (year%400==0| | (year%4==0&&year%100!=0))

printf ("%d years is a leap year \ n";

Else

printf ("%d years is not a leap year \ n";

printf ("Whether to continue: y/n?\n");

GetChar ();

C=getchar ();

}while (c== ' Y ' | | c== ' Y ');

return 0;

}

5, the 5th Small program: Structure of the structure of the members of the body

#include <stdio.h>

typedef struct date{

int year;

int month;

int day;

}mydate;

typedef struct stu{

int number;

MyDate birthday;

Char name[20];

Char sex[10];

int score;

}stu;

int main ()

{

Stu Students[5] = {

{001,{1991,1,1}, "Laoer", "Nan", 87},

{002,{1992,2,2}, "Laoer", "NV", 82},

{003,{1993,3,3}, "Laosan", "Nan", 88},

{004,{1994,4,4}, "Laosi", "Nan", 84},

{005,{1995,5,5}, "Laowu", "Nan", 85}

};

for (int i=0;i<5-1;i++) {

for (int j=0;j<5-1-i;j++) {

if (Students[j].score<students[j+1].score) {

Stu Temp=students[j];

STUDENTS[J]=STUDENTS[J+1]; //struct can be directly assigned value

Students[j+1]=temp;

}

}

}

printf ("%d%d-%d-%d%s%s%d\n", Students[i].number,students[i].birthday.year,students[i].birthday.month,students[i ].birthday.day,students[i].name,students[i].sex,students[i].score);

}

}

6, two-dimensional array learning: Generate 2 Rows 3 columns of the random number between 1-50 to sort and print, print the maximum number

#include <stdio.h>

#include <stdlib.h>

int main ()

{

int number[2][3]={0};

for (int i=0;i<2;i++) {

for (int j=0;j<3;j++) {

Number[i][j]=arc4random ()%50;

printf ("%d", number[i][j]);

}

printf ("\ n");

}

int max=0;

for (int i=0;i<2;i++) {

for (int j=0;j<3;j++) {

if (Max<number[i][j]) {

MAX=NUMBER[I][J];

}

}

}

printf ("%d\n", Max);

for (int i=0;i<2;i++) {

for (int j=0;j<3;j++) {

if (Number[i][j]==max) {

printf ("%d%d", i,j);

}

}

}

return 0;

}

7. Enter a number to calculate the factorial

#include <stdio.h>

int main ()

{

int i;

int sum=1;

printf ("Please enter:");

scanf ("%d", &i);

for (int j=1;j<=i;j++) {

Sum*=j;

}

printf ("Factorial of%d is%d\n", i,sum);

}

8. Enter a date to determine the day of the year

typedef struct date{

int year;

int mouth;

int day;

}date;

Judging leap years

int pd_year (int a);

int pd_year (int a)

{

if (a%400==0| | (a%4==0&&a%100!=0))

return 1;

Else

return 0;

}

int Pd_day (struct date date);

int Pd_day (struct date date)

{

int sum=0,days[] = {31,28,31,30,31,30,31,31,30,31,30,31};

for (int i=0; i<date.mouth-1; i++)

Sum+=days[i];

if (date.mouth>2)

Sum=sum+date.day+pd_year (date.year);

Else

Sum=sum+date.day;

return sum;

}

int main (void) {

struct date date;

int n;

printf ("Please enter the date (month and day) \ n");

scanf ("%d%d%d", &date.year,&date.mouth,&date.day);

N=pd_day ((Date));

printf ("The Day of the year is%d days", n);

}

return 0;

}

9, enter the score, Judge Abcde, three times the wrong chance

#include <stdio.h>

int main (void)

{

int gread=0;

int i=3;

printf ("Please enter your score: \ n");

scanf ("%d", &gread);

while (gread==0| | Gread) {

if (gread>=0&&gread<=100) {

Switch (GREAD/10) {

Case 10:

Case 9:

printf ("Your grades are a\n");

Break

Case 8:

printf ("Your grades are b\n");

Break

Case 7:

printf ("Your grades are c\n");

Break

Case 6:

printf ("Your grades are d\n");

Break

Case 5:

Case 4:

Case 3:

Case 2:

Case 1:

Case 0:

printf ("Your grades are e\n");

Break

Default

Break

}

}else

{

I.;

if (i>0) {

printf ("Input error, you also have%d input opportunities!") \ n ", i);}

else{

Break

}

}

scanf ("%d", &gread);

}

return 0;

}

C Language Learning record "July"