C，unsigned int（a）^ unsigned int（b）和unsigned int（a ^ b）之间有什么区别？

Question

在测试平台中，我编写如下程序：

int a, b;
scanf_s("%d%d",&a,&b);
unsigned int c = a^b;//this can not pass
unsigned int c = unsigned int(a)^unsigned int(b) //this can pass
int cnt = 0;
while (c){
    cnt++;
    c = c&(c-1);
}
printf("%d\n",cnt);

Answer 1

你的程序中有一些严重的语法错误我怀疑它编译尝试使用以下程序，它应该工作正常。

您的代码中存在以下问题。

• c被宣布两次

• 将int转换为unsigned int时出错了

  int main()
  {
  
    int a, b;
    scanf_s("%d%d",&a,&b);
    unsigned int c = a^b;//this can not pass
    c = (unsigned int)a^( unsigned int )b;//this can pass
    int cnt = 0;
    while (c){
        cnt++;
        c = c&(c-1);
    }
    printf("%d\n",cnt);
  
    return 0; 
  }