C language-9 basic programming examples
(They are relatively simple, so I don’t need to comment. If you don’t understand the comment area, please ask me, don’t forget to follow the point of praise)
1. Greatest common divisor:
#include<stdio.h>
int main(){
int x, y,number;
scanf("%d%d",&x,&y);
if (x > y){
x = x^y;
y = x^y;
x = x^y;
}
for (int i = 1; i <= x;i++){
if (x%i==0&&y%i==0){
number = i;
}
}
printf("%d\n",number);
return 0;
}
2. Print leap years between 1000 and 2000:
#include<stdio.h>
int main(){
int year=1000;
while (year<= 2000){
if (year%400==0||(year%4==0&&year%100!=0)){
printf("%d ",year);
}
year++;
}
printf("\n");
return 0;
}
3. Write a code: print prime numbers between 100 and 200:
#include<stdio.h>
int main(){
int i, j;
for (i = 100; i <= 200;++i){
for (j = 2; j<i&&(i%j!=0);++j){
}
if (j==i){
printf("%d ",i);
}
}
printf("\n");
return 0;
}
4. Write a program to count how many numbers 9 appear in all integers from 1 to 100:
#include<stdio.h>
int main(){
int num=0;
for (int i = 1; i <= 100;++i){
if ((i+1)%10==0){
num++;
}
}
printf("%d\n",num);
return 0;
}
5. Calculate the value of 1/1-1/2+1/3-1/4+1/5 …… + 1/99-1/100, and print out the result:
#include<stdio.h>
int main(){
int i = 1;
float sum = 0;
for (float j = 1; j <= 100;++j){
sum = sum + i / j;
i = (-i);
}
printf("%.2f\n",sum);
system("pause");
return 0;
}
6. Find the maximum value among 10 integers:
#include<stdio.h>
int main(){
int num[] = {
10,20,0,8,9,5,99,100,1000,12};
int Max=num[0];
for (int i = 1; i < 10;++i){
if (Max<num[i]){
Max = num[i];
}
}
printf("%d\n",Max);
return 0;
7. Output 9*9 multiplication formula table on the screen:
#include<stdio.h>
int main(){
for (int i = 1; i < 10;++i){
for (int j = 1; j < 10;++j){
printf("%d*%d=%d ",i,j,i*j);
}
printf("\n");
}
return 0;
}
8. Guess the number game:
#include<stdio.h>
#include<stdlib.h>
#include<time.h>
int main(){
int number[100],i,num;
srand(time(NULL));//生成种子
for (i = 0; i < 100;++i){
number[i] = rand()%10+10;//生成20以内随机数
}
i = rand() % 100;//随机抽取100以内的下标
printf("请输入所猜的一位20以内的数：");
scanf("%d",&num);
if (number[i]==num){
printf("找到了，为%d\n",number[i]);
}
else {
printf("没找到！\n");
}
system("pause");
return 0;
}
9. Write code to find a specific number in an integer ordered array:
#include<stdio.h>
int main(){
int number;
int num[] = {
1, 8 ,11,20,60,100,1211};
int len = sizeof(num) / sizeof(num[0]);
int left=0, right=len-1,mid;
scanf("%d",&number);
while (left<=right){
mid = (left + right) / 2;
if (number>num[mid]){
left = mid + 1;
}
else if (number<num[mid]){
right = mid - 1;
}
else{
printf("找到了，在数组中的下标为%d\n",mid);
break;
}
if (left>right){
printf("没找到！\n");
}
}
return 0;
}
The above is written by myself, all executable, for reference only, don’t spray if you don’t like it, if you like it, follow it, like it.