C ——程序设计题

#include
#include
int main()
{
 double a,b,c,t,x,y;
 scanf("%lf %lf %lf",&a,&b,&c);
 t=b*b-4*a*c;
 if(a!=0 && t>0){
  x=1.0*(-b+sqrt(t))/(2*a);
  y=1.0*(-b-sqrt(t))/(2*a);
  printf("%.2fn",x);
  printf("%.2fn",y);
 }else if(a!=0 && t==0){
  x=(-b)/(2*a);
  printf("%.2f",x);
 }else if(a!=0 && t<0){
  x=1.0*(-b)/(2*a);
  y=1.0*sqrt(-t)/(2*a);
     if( x!= 0){
  printf("%.2f+%.2fin",x,y);
  printf("%.2f-%.2fin",x,y);
       }else{
        printf("0.00+%.2fin",y);
      printf("0.00-%.2fin",y);
    }
 }else if(a==0 && b==0 && c==0){
  printf("Zero Equation");
 }else if(a==0 && b==0 && c!=0){
  printf("Not An Equation");
 }else{
  x=-1.0*(c/b);
  printf("%.2f",x);
 }
 return 0;
 } 

 
#include
#include
int main()
{
	int i,n,total=0,score,max,min;
	double average;
	char *p;
	
	printf("Enter n:");
	scanf("%d",&n);
	
	if((p=(int *)calloc(n,sizeof(int)))==NULL){
		printf("Not able to allocate memorry.n");
		exit(1);
	}
	printf("Enter %d score ",n);                
	
	for(i=0;imax){
			max=*(p+i);
		}
		else if(*(p+i) 
#include 
#define MAXN 10

struct student{
    int num;
    char name[20];
    int score;
    char grade;
};

int set_grade( struct student *p, int n );

int main()
{   struct student stu[MAXN], *ptr;
    int n, i, count;

    ptr = stu;
    scanf("%dn", &n);
    for(i = 0; i < n; i++){
       scanf("%d%s%d", &stu[i].num, stu[i].name, &stu[i].score);
    } 
   count = set_grade(ptr, n);
   printf("The count for failed (<60): %dn", count);
   printf("The grades:n"); 
   for(i = 0; i < n; i++)
       printf("%d %s %cn", stu[i].num, stu[i].name, stu[i].grade);
    return 0;
}
int set_grade( struct student *p, int n )
{
    int i, count=0;
    struct student;
    for(i=0; i= 85){
            p[i].grade = 'A';
        }else if(p[i].score >= 70){
            p[i].grade = 'B';
        }else if(p[i].score >= 60){
            p[i].grade = 'C';
        }else {
            p[i].grade = 'D';
            count++;
        }
    }
    return count;
}
 
#include
int main()
{
	int i,year,month,day,lastday,sum=0,Final;
	int a[11]={31,28,31,30,31,30,31,31,30,31,30,31};

	scanf("%d %d %d",&year,&month,&day);
	if(year%4==0&&year%100!=0||year%400==0){
		lastday=366;
		a[1]=29;
	}else{
		lastday=365;
	}
	for(i=0;i