golang 查找数组中最小数的泛型函数

golang里要实现查找数组最小数的泛型函数,需要用到类型开关。

gol的类型开关写法:

switch v.(type) {
    case int:
    case float64:
    case string:
}

思路就是遍历数组,遇到更小的数保存下来,函数退出返回那个数。

golang代码:

package main
import (
  "fmt"
)
func Minimum(first interface{}, rest ...interface{}) interface{}{
  minimum := first
  for _, v := range rest {
    switch v.(type) {
      case int:
        if v := v.(int); v < minimum.(int) {
          minimum = v 
        }  
      case float64:
        if v := v.(float64); v < minimum.(float64) {
          minimum = v 
        }  
      case string:
        if v := v.(string); v < minimum.(string) {
          minimum = v 
        }  
    }  
  }  
  return minimum
}
func main() {
  i := Minimum(1, 3, 5, 7, 9, 10, -1, 1).(int)
  fmt.Printf("i = %d\n", i)
}

clang:

#include <stdio.h>
int min_int(void *v1, void *v2) {
  return *(int *)v1 > *(int *)v2;
}
int min_double(void *v1, void *v2) {
  return *(double *)v1 > *(double *)v2;
}
void *minimum(void *base, int size, int esize, int (*min_cmp)(void *, void *)) {
  int i;
  void *mini = base;
  for (i = 1; i < size; i++) {
    if (min_cmp(mini, base + i * esize))
      mini = base + i * esize;
  }  
  return mini;
}
#define ARR_LEN(arr) sizeof(arr) / sizeof((arr)[0])
#define ARR_ESIZE(arr) sizeof((arr)[0])
int main() {
  void *min;
  int arr_int[] = {0, 5, 6, 7, 8, 9, -1, 2}; 
  min = minimum(arr_int, ARR_LEN(arr_int), ARR_ESIZE(arr_int), min_int);
  printf("%d\n", *(int *)min);
  double arr_double[] = {1.1, 2.2, 3.3, 4.4, 5.5, 6.6, -3.14, 99};
  min = minimum(arr_double, ARR_LEN(arr_double), ARR_ESIZE(arr_double), min_double);
  printf("%lf\n", *(double *)min);
  return 0;
}

本文来自:开源中国博客

感谢作者:guonaihong

查看原文:golang 查找数组中最小数的泛型函数

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