C language (? Two-dimensional array, string array, multidimensional array) class notes plus homework

//

Main.m

1-19 Course Notes

Two-dimensional arrays, string arrays, multidimensional arrays

Lecturer: Xiao Hui

Author: Wang Xuewen

Created by Lanouhn on 15/1/19.

Copyright (c) 2015 Lanouhn. All rights reserved.

//

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[]) {

/*

One-dimensional arrays

int a[10] = {1, 2, 3, 4, 5};

Two-dimensional array, one dimension more than one-dimensional array (one more element subscript)

int b[2][3] = {1, 2, 3, 4, 5, 6};

Definition of a two-dimensional array

Format:

Data type array name [number of rows] [number of columns] = {value 1, value 2, ...} ；

Number of elements in a two-dimensional array = number of rows * columns;

Other forms of definition

1. Can be omitted when assigning value, the default value is 0

int array1[2][3] = {1, 2, 3};

2. The number of rows can be omitted, the number of elements and the number of columns is determined;

int array2[][3] = {1, 2, 3, 4};

The number of columns cannot be omitted

int array3[2][] = {1, 2, 3, 4, 5}; Error

int array4[][] = {1, 2, 3, 4}; Error

Use of two-bit arrays

Gets the format of the element

Array name [number of rows] [number of columns]

Note: The number of rows and columns starts at 0

int array[3][2] = {1, 2, 3, 4, 5, 6};

Get element

ARRAY[0][0];

ARRAY[0][1];

ARRAY[1][0];

ARRAY[1][1];

ARRAY[2][0];

ARRAY[2][1];

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

for (int j = 0; J < 2; J + +) {

printf ("array[%d][%d] =%d\n", I, J, Array[i][j]);

}

}

Assigning a value to an element of an array

Define an array of 5 rows and 6 columns, assign values to each array randomly, take a range [55,88], and find the location of the maximum and minimum values

Clear Cache Command + SHIFT + K;

int a[5][6] = {0};

int max = 0, min = 89;

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

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

A[I][J] = arc4random ()% 34 + 55;

printf ("a[%d][%d] =%d", I, J, A[i][j]);

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

max = A[i][j];

}

if (min > A[i][j]) {

min = A[i][j];

}

}

}

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

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

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

printf ("\ n max a[%d][%d] =%d\n", I, J, A[i][j]);

}

if (min = = A[i][j]) {

printf ("min a[%d][%d] =%d\n", I, J, A[i][j]);

}

}

}

int a[3][4] = {0};

int b[4][3] = {0};

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

for (int j = 0; J < 4; J + +) {

A[I][J] = arc4random ()% 11 + 50;

printf ("a[%d][%d] =%d", I, J, A[i][j]);

} printf ("\ n");

}

printf ("After Exchange: \ n");

for (int j = 0; J < 4; J + +) {

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

B[j][i] = A[i][j];

printf ("b[%d][%d] =%d", j, I, B[j][i]);

}printf ("\ n");

}

A character array in which the elements of the array contents are characters (char)

Array of strings: elements stored in an array are strings

Character array, also called string

Array of strings: The elements in the array are character arrays, array arrays, so the string array is a two-dimensional array

Character array

Char string1[6] = {' A ', ' P ', ' P ', ' l ', ' e ', ' n '};

String

Char string2[6] = "Apple";

Array of strings

Char String3[3][7] = {"Apple", "Xiaomi", "Nokia"};

Output string array

printf ("%s\n", string1);

1. Character output

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

for (int j = 0; J < 7 && string3[i][j]! = ' + '; j + +) {

printf ("%c", String3[i][j]);

}printf ("\ n");

}

printf ("%s\n", string2);

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

printf ("%s\n", String3[i]);

}

Create an array to hold the names of the students around you and find out whose names are the longest.

Char a[4][20] = {"Weizijian", "Wanhao", "Yaochengzheng", "Wangxuewen"};

unsigned long max = 0;

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

if (Max < strlen (A[i])) {

max = strlen (A[i]);

}

}

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

if (max = = strlen (A[i])) {

printf ("Longest name:%s\n", A[i]);

}

}

Input string

char c = 0;

scanf ("%c", &c);

Input string

Char m[10] = {0};

scanf ("%s", m); No need to add &

Input string array

Char k[3][10] = {0};

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

scanf ("%s", K[i]);

}

scanf ("%s%s%s", K[0], k[1], k[2]);

Sort the names of the students around them

Char name[][20] = {"Wanhao", "Weizijian", "Wangxuewen", "Yaochengzheng"};

for (int i = 0; i < 4-1; i++) {

for (int j = 0; J < 4-1-I; j + +) {

if (strcmp (Name[i], name[i+1]) > 0) {

Char a[20] = {0};

strcpy (A, name[i]);

strcpy (Name[i], name[i + 1]);

strcpy (Name[i + 1], a);

}

}

}

Output results

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

printf ("%s\n", Name[i]);

}

Bubble sort

int array[5] = {12, 33, 22, 1, 20};

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

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

if (Array[j] > array[j + 1]) {

int temp = Array[j];

ARRAY[J] = array[j + 1];

Array[j + 1] = temp;

}

}

}

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

printf ("%d\n", Array[i]);

}

*/

1. (* *) There is a two-dimensional array of 3 rows and 4 columns, which requires programming to find the largest element and output the row and column in which it resides.

int a[3][4] = {1, 2, 3, 4, 5, 6, 7, 8, 5, 4, 8, 3};

int max = 0;

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

for (int j = 0; J < 4; J + +) {

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

max = A[i][j];

//            }

//        }

//    }

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

for (int j = 0; J < 4; J + +) {

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

printf ("Maximum value in%d rows%d \ n", i + 1, j+ 1);

//            }

//        }

//    }

2, (* *) enter 6 strings and output them in order from small to large.

Char a[6][20] = {0};

printf ("Please enter 6 strings:");

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

scanf ("%s", A[i]);

//    }

for (int i = 0; i < 6-1; i++) {

for (int j = 0; J < 6-1-I; j + +) {

if (strcmp (A[j], a[j + 1])) {

Char b[20] = {0};

strcpy (b, a[j]);

strcpy (A[j], a[j + 1]);

strcpy (A[j + 1], b);

//            }

//        }

//    }

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

printf ("%s\n", A[i]);

//    }

3, (* *) randomly generated a three-dimensional array, the average of programming depth, stored in a two-dimensional array (equivalent to a Rubik's Cube from the above).

int a[4][5][6] = {0};

Float B[4][5] = {0};

//

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

for (int j = 0; J < 5; J + +) {

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

A[i][j][k] = arc4random ()% 20;

printf ("a[%d][%d][%d] =%3d", I, J, K, A[i][j][k]);

}printf ("\ n");

//        }

//    }

for (int j = 0; J < 5; J + +) {

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

float sum = 0.0;

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

sum = sum + a[i][j][k];

B[J][K] = sum;

//            }

printf ("b[%d][%d] =%5.2f", J, K, B[j][k]/4);

}printf ("\ n");

//    }

return 0;

}

C language (? Two-dimensional array, string array, multidimensional array) class notes plus homework