为什么会出现警告？passing argument 2 of 'strcmp' makes pointer from integer without a cast

为什么会出现警告？passing argument 2 of 'strcmp' makes pointer from integer without a cast

string 是字符 不能拿来跟字符串比较·········
#include
#include
void main()
{
    char string;
    char str[3][20];
    int i;
    for(i=0;i<3;i++)
        gets(str[i]);
    if (strcmp(str[0],str[1])>0)
        strcpy(string,str[0]);   //字符串复制到字符 错误
    else
        strcpy(string,str[1]);   //字符串复制到字符 错误
    if(strcmp(str[2],string)>0)  //字符串与字符比较 错误
        strcpy(string,str[2]);   //字符串复制到字符 错误
printf("%s",string);         //以字符串形式输出字符 错误
}