没有使用cmath.h，提示cmath.h一大堆错误
#include<stdio.h>#include<string>#define LEN 25#define SIZE 5void showinfo(struct person info[],int size);struct names { char firstname[LEN]; char middlename[LEN]; char lastname[LEN];};struct person { int ssn; struct names name;};int main(void){ int i; struct person people[SIZE]; for(i=0;i<SIZE;i++) { printf("Enter first name:"); gets(people[i].name.firstname); printf("Enter middle name:"); gets(people[i].name.middlename); printf("Enter last name:"); gets(people[i].name.lastname)==NULL; printf("Enter SSN:"); scanf("%d",people[i].ssn); while(getchar()!='\n'); } showinfo(people,SIZE); return 0;}void showinfo(person info[],int size){ int i; for(i=0;i<size;i++) { printf("%s, %s",info[i].name.lastname,info[i].name.firstname); if(info[i].name.middlename[0]!='\0') printf(" %c.",info[i].name.middlename[0]); printf(" - %d\n",info[i].ssn); }}