Series articles 《C Language classics 100 example 》 Continuous creation , Welcome your attention and support .
Like the students remember to like 、 forward 、 Collection ～
follow-up C Language classics 100 Examples will be pdf And code forms to official account.
Welcome to your attention ： Computational advertising ecology Check immediately
1 subject
function ：fun()
function ： Count the number of people of all ages
describe ：
N The age is obtained by calling a random function , And stored in the age in
The function is required to 0-9 In the age group d[0] in , hold 10-19 In the age group d[1] in , By analogy . hold 100 Age and above d[10] in
The result is output in the main function
2 Ideas
Random use rand() function , The header file is #include <stdlib.h>
rand() Function generates integers in a specified order , Therefore, the same two values are printed each time the above statement is executed , So C The randomness of language is not the real randomness , Sometimes called pseudo-random numbers , Use rand() Before generating random numbers, we need to use the initialization function of the random generator srand(unsigned seed)（ Also located in stdlib.h in ） Initialize the pseudo-random number sequence ,seed Also called random seed , Generally speaking, it is , If provided each time seed The same thing , Finally, several random values generated in each round are the same , So it's called pseudo-random number , So you need to provide different seed To achieve complete randomness , We usually use time functions time(NULL) As seed , Because the time values are different every second , But it can't be used in this question time This tool
3 Code
#include <stdio.h>
#include <stdlib.h>
#define M 11
#define N 100
/**
function ：fun()
function ： Count the number of people of all ages
describe ：
N The age is obtained by calling a random function , And stored in the age in
The function is required to 0-9 In the age group d[0] in , hold 10-19 In the age group d[1] in , By analogy . hold 100 Age and above d[10] in
The result is output in the main function
**/
void fun(int *age, int *d) {
for (int i = 0; i < N; ++i) {
if (*(age+i)<100) {
d[(*(age+i))/10] += 1;
} else {
d[M-1] += 1;
}
}
}
int main(int argc, char const *argv[]) {
int age[N]; // 100 Users
int d[M]={0}; // 11 Age groups
for (int i = 0; i < N; ++i) {
*(age+i) = rand()%121; // What is the age range 0-120
}
fun(age, d);
printf(" Number of people by age ：\n");
for (int i = 0; i < M; ++i) {
printf("%d ", d[i]);
}
printf("\n");
}
Sample results ：
$ gcc ex004.c -o demo
$ ./demo
Number of people by age ：
10 9 8 4 10 8 7 7 6 11 20
-- END --
Please remember to like this article 、 forward 、 Collection ~
More , Welcome to our official account. ： Computational advertising ecology
follow-up C Language classics 100 Examples will be pdf And code forms to official account.
It also brings more articles and dry goods ！
