c语言中动态数组的建立

 1 #define _CRT_SECURE_NO_DEPRECATE
 2 #include<stdio.h>
 3 #include<stdlib.h>
 4 void createOneDimensionalVector(){
 5     int n, i;
 6     int *arr;
 7     scanf("%d",&n);
 8     arr = (int*)malloc(sizeof(int)*n);
 9     for (i = 0; i < n; i++)
10         arr[i] = i;
11     for (i = 0; i < n; i++)
12         printf("%d\t",arr[i]);
13 }
14 
15 int main(){
16     createOneDimensionalVector();
17 
18     return 0;
19 }

 1 void createTwoDimensionalVector(){
 2     int n=3, m=4;
 3     int** a;
 4     a = (int**)malloc(sizeof(int*)*n);//创建一个指针数组，把指针数组的地址赋值给a
 5     for (int i = 0; i < n; i++)
 6         a[i] = (int*)malloc(sizeof(int)*m);//给第二维分配空间
 7 
 8     for (int i = 0; i < n; i++){
 9         for (int j = 0; j < m; j++)
10             a[i][j] = i + j;
11     }
12 
13     for (int i = 0; i < n; i++){
14         for (int j = 0; j < m; j++)
15             printf("%d\t",a[i][j]);
16         printf("\n");
17     }
18 }
19 int main(){
20     createTwoDimensionalVector();
21 
22     return 0;
23 }