如何在c中排序结构数组

I need to sort an array of structures, each one having a string that is a name. I want to do a simple sorting using bubble sort and strcmp, but my code doesn't work, it outputs the last name I've entered for the entire loop.

我需要对结构数组进行排序，每个结构都有一个名称为string的字符串。我想使用bubble sort和strcmp进行简单的排序，但是我的代码不起作用，它输出我为整个循环输入的姓。

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define SIZE 16
#define N 5

struct Prova {
  char nome[SIZE];
};

void sort(struct Prova *ptr) {
  char temp[SIZE];

  for (int i = 0; i < N; i++) {
    for (int j = i + 1; j < N; j++) {
      if (strcmp((ptr + i)->nome, (ptr + j)->nome) < 0) {
        strcpy(temp, (ptr + i)->nome);
        strcpy((ptr + i)->nome, (ptr + j)->nome);
        strcpy(temp, (ptr + j)->nome);
      }
    }
  }
}

int main() {
  struct Prova * ptr;
  ptr = (struct Prova*) malloc(N * sizeof(struct Prova));

  for (int i = 0; i < N; i++) {
    scanf(" %s", (ptr + i)->nome);
  }

  sort(ptr);

  for (int i = 0; i < N; i++) {
    printf("%s\n", (ptr + i)->nome);
  }
}

Basically it needs to sort all the names in the structures and print them in ascending order, using the first letter of the name.

基本上，它需要对结构中的所有名称进行排序，并使用名称的第一个字母按升序打印它们。

UPDATED: Later i noticed that mistake in my code, thank you all for the replies/suggestions. Now is this:

更新:后来我发现我的代码有错误，谢谢大家的回复/建议。现在是这样的:

  for(int i = 0; i < N - 1; i++)
{
  for(int j = i+1; j < N; j++)
  {
    // < 0 = Z-A  invece > 0 = A-Z
    if(strcmp((ptr+i)->nome,(ptr+j)->nome) > 0)
      {
        strcpy(temp, (ptr+i)->nome);
        strcpy((ptr+i)->nome,(ptr+j)->nome);
        strcpy((ptr+j)->nome, temp);
      }
  }

}

2 个解决方案

#1

OP mis-coded

    strcpy(temp, (ptr + i)->nome);
    strcpy((ptr + i)->nome, (ptr + j)->nome);
    // strcpy(temp, (ptr + j)->nome);
    strcpy((ptr + j)->nome, temp);

Many other improvements possible

许多其他可能的改进

Use qsort() @Karsten Koop
使用qsort()@Karsten Koop
Validate inputs. Better to use fgets().
验证输入。最好使用fgets()。
Simplify, check and free --> struct Prova *ptr = malloc(sizeof *ptr * N); if (ptr == NULL) Handle_OutOfMemory(); ... // use ptr ... free(ptr);
简化、检查、*——>结构Prova *ptr = malloc(sizeof *ptr * N);if (ptr == NULL) Handle_OutOfMemory();…/ /使用ptr……免费(ptr);

#2

The problem is the last strcpy statement. You need to reverse the parameters like this:

问题是最后的strcpy语句。你需要像这样反转参数:

for (int i = 0; i < N; i++) {
    for (int j = i + 1; j < N; j++) {
      if (strcmp((ptr + i)->nome, (ptr + j)->nome) < 0) {
        strcpy(temp, (ptr + i)->nome);
        strcpy((ptr + i)->nome, (ptr + j)->nome);
        strcpy((ptr + j)->nome, temp);
      }
    }
  }
}

#1