排序使用程序指針

Question

我有一個計劃：

• 給出數字的序列，甚至
• 按升序排序號碼，
• 按降序排序奇數和
• 將排序後的偶數添加到數組，然後排序奇數。

實施例：

Input: 1, 2, 3, 4, 5, 6 
Expected output: 2, 4, 6, 5, 3, 1 
Actual output: 1578032, 0, 3, 6, 6487408, 0 

這裏是我的代碼：

#include <stdio.h> 

int main() { 
    input(); 
} 
int input() { 
    int n; 
    printf("Enter The Number Of Elements You Want To Enter : "); 
    scanf("%d", & n); 
    int * ptr, i, ev = 0, od = 0; 
    ptr = (int *) calloc(n, sizeof(int)); 
    for (i = 0; i < n; i++) { 
     printf("Enter Number : "); 
     scanf("%d", (ptr + i)); 
     if (* (ptr + i) % 2 == 0) { 
      ev++; 
     } else { 
      od++; 
     } 
    } 

    sorteven(& ptr, ev, od, n); 
} 
int sorteven(int * ptr, int ev, int od, int n) { 
    int i, j = 0, swap = 0, * ptreven; 
    ptreven = (int *) calloc(ev, sizeof(int)); 
    for (i = 0; i < n; i++) { 
     if (* (ptr + i) % 2 == 0) { * 
      (ptreven + j) = * (ptr + i); 
      j++; 
     } 
    } 
    for (i = 0; i < ev - 1; i++) { 
     for (j = 0; j < ev - i - 1; j++) { 
      if (* (ptreven + j) > * (ptreven + j + 1)) { 
       swap = * (ptreven + j); * 
       (ptreven + j) = * (ptreven + j + 1); * 
       (ptreven + j + 1) = swap; 
      } 
     } 
    } 
    sortodd(& ptr, ev, od, n, & ptreven); 
} 
int sortodd(int * ptr, int ev, int od, int n, int ptreven) { 
    int i, k = 0, swap = 0, * ptrodd, j; 
    ptrodd = (int *) calloc(od, sizeof(int)); 
    for (i = 0; i < n; i++) { 
     if (* (ptr + i) % 2 != 0) { * 
      (ptrodd + k) = * (ptr + i); 
      k++; 
     } 
    } 
    for (i = 0; i < od - 1; i++) { 
     for (j = 0; j < od - i - 1; j++) { 
      if (* (ptrodd + j) < * (ptrodd + j + 1)) { 
       swap = * (ptrodd + j); * 
       (ptrodd + j) = * (ptrodd + j + 1); * 
       (ptrodd + j + 1) = swap; 
      } 
     } 
    } 
    merge(& ptr, ev, od, n, & ptreven, & ptrodd); 
} 
int merge(int * ptr, int ev, int od, int n, int * ptreven, int * ptrodd) { 
    int * ptrmerge, i, j; 
    ptrmerge = (int *) calloc(n, sizeof(int)); 
    for (i = 0; i < ev; i++) { * 
     (ptrmerge + i) = * (ptreven + i); 
    } 
    for (i = ev, j = 0; i < n; i++, j++) { * 
     (ptrmerge + i) = * (ptrodd + j); 
    } 
    display(& ptrmerge, n); 
} 
int display(int * ptrmerge, int n) { 
    int i; 
    printf("OUTPUT : "); 
    for (i = 0; i < n; i++) { 
     printf(" %d ", * (ptrmerge + i)); 
    } 
} 

Answer 1

這樣

#include <stdio.h> 
#include <stdlib.h> 

void input(void); 

int main(void){ 
    input(); 
} 

void sorteven(int *ptr, int n); 
void sortodd(int *ptr, int n); 
void display(int *ptt, int n); 

void input(void){ 
    int n; 
    printf("Enter The Number Of Elements You Want To Enter : ");fflush(stdout); 
    scanf("%d", &n); 

    int *ptr, i, ev = 0, od = 0; 
    if((ptr = calloc(n, sizeof(int)))==NULL){ 
     perror("malloc"); 
     exit(EXIT_FAILURE); 
    } 

    for (i = 0; i < n; i++){ 
     int v; 
     printf("Enter Number : ");fflush(stdout); 
     scanf("%d", &v); 

     if(v % 2 == 0){ 
      ptr[ev++] = v; 
     } else { 
      ptr[n - ++od] = v; 
     } 
    } 

    sorteven(ptr, ev); 
    sortodd(ptr + ev, od); 
    display(ptr, n); 
    free(ptr); 
} 

void sorteven(int *ptr, int n){ 
//sort to ascending order 
    int i, j, temp; 

    for (i = 0; i < n - 1; i++){ 
     for (j = 0; j < n - i - 1; j++){ 
      if(ptr[j] > ptr[j + 1]){ 
       int temp = ptr[j]; 
       ptr[j] = ptr[j + 1]; 
       ptr[j + 1] = temp; 
      } 
     } 
    } 
} 

void sortodd(int *ptr, int n){ 
//sort to descending order 
    int i, j, temp; 

    for (i = 0; i < n - 1; i++){ 
     for (j = 0; j < n - i - 1; j++){ 
      if(ptr[j] < ptr[j + 1]){ 
       int temp = ptr[j]; 
       ptr[j] = ptr[j + 1]; 
       ptr[j + 1] = temp; 
      } 
     } 
    } 
} 

void display(int *ptr, int n){ 
    int i; 

    printf("\nOUTPUT : "); 
    for (i = 0; i < n; i++){ 
     if(i) 
      putchar(' '); 
     printf("%d", ptr[i]); 
    } 
    putchar('\n'); 
}