One-dimensional arrays, array sorting, character arrays

1. One-dimensional arrays

Arrays are constructed data types

Distinguish between array elements and arrays (int a[10] a[10])

The subscript must be guaranteed not to cross the border

An array is a whole and cannot be directly involved in an operation, only a single element can be processed.

2. Array sort (bubble sort)

int a[7] = {3, 1, 7, 23, 12, 87, 2};

The outer loop controls the number of trips to compare, and n elements need to compare n-1 times

for (int i = 0; i < 6; i++) {

Inner loop control in each trip to compare the number of times, each come in one less comparison

for (int j = 0; J < 6-i; J + +) {

If the previous element is larger than the latter, the swap position

if (A[j] < A[j + 1]) {

int temp = A[j];

A[J] = a[j + 1];

A[j + 1] = temp;

}

}

}

Print a sorted array

for (int i = 0; i < 7; i++) {

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

}

Select sort

int a[5] = {7, 4, 6, 2, 1};

int k = 0;

for (int i = 0; i < 4; i++) {

K = i;//assumes that the a[i] element is the minimum value

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

if (A[k] > A[j]) {

K = J;

}

}

if (i! = k) {

int temp = A[i];

A[i] = a[k];

A[K] = temp;

}

}

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

printf ("%-3d", A[i]);

}

3, character array

Char c[] = {' I ', ' P ', ' h ', ' o ', ' n ', ' e '};//length of 6

C language string ends with a

Char a[6] = "iPhone";//Length of 7 ' + '

unsigned long result = strlen (a);//The calculation is not required to meet the end of the

unsigned long s = sizeof (a);//sizeof () Memory size

printf ("%s", a);

The space occupied by the string is at least 1 larger than the string length, because the string ends with '/'. The string handler provided by the system determines whether the string ends according to '% '.

printf ("%ld", result);

printf ("%ld", s);

Strlen () Calculate string? length

strcpy () string copy shell

strcat () string concatenation

strcmp () string? comparison

One-dimensional arrays, array sorting, character arrays