第二章
#include<stdio.h> int main(void) { double x,y; printf("Enter x (x>=0:\n"); scanf("%lf",&x); if(x<=15){ y=4*x/3; } else{ y=2.5*x-10.5; } printf("y=f(%f)=%.2f\n",x,y); return 0; }
/*"Hello world!"*/ #include<stdio.h> int main(void) { printf("Hello World!\n"); return 0; }
#include<stdio.h> int main(void) { printf("Programming is fun.\n"); printf("And programming in C is even more fun!\n"); return 0; }
#include<stdio.h> int main(void) { /*定义两个整型变量,celsius表示摄氏度,fahr表示华氏度*/ int celsius,fahr; fahr=100; celsius=5*(fahr-32)/9; printf("fahr=%d,celsius=%d\n",fahr,celsius); return 0; }
#include<stdio.h> int main(void) { double x,y; printf("Enter x(x>=0):\n"); scanf("%lf",&x); if (x<=15){ y=4*x/3; } else{ y=2.5*x-10.5; } printf("y=f(%f)=%.2f\n",x,y); return 0; }
#include<stdio.h> int main(void) { int fahr,lower,upper; double celsius; printf("Enter lower:"); scanf("%d",&lower); printf("Enter upper:"); scanf("%d",&upper); printf("fahr celsius\n"); for(fahr=lower;fahr<=upper;fahr++){ celsius=(5.0/9.0)*(fahr-32); printf("%d%6.1f\n",fahr,celsius); } return 0; }
#include<stdio.h> int main(void) { int i,n,sum; printf("Enter n:"); scanf("%d",&n); sum=0; for(i=1;i<=n;i++){ sum=sum+i; } printf("Sum of numbers from 1 to %d is %d\n",n,sum); return 0; }
#include<stdio.h> int main(void) { int denominator,flag,i,n; double item,sum; printf("Enter n:"); scanf("%d",&n); flag=1; denominator=1; sum=0; for(i=1;i<=n;i++){ item=flag*1.0/denominator; sum=sum+item; flag=-flag; denominator=denominator+2; } printf("sum=%f\n",sum); return 0; }
#include<stdio.h> int main(void) { int i,n; double product; printf("Enter n:"); scanf("%d",&n); product=1; for(i=1;i<=n;i++){ product=product*i; } printf("product=%.0f\n",product); return 0; }
#include<stdio.h> #include<math.h> int main(void) { int i,n; double power; printf("Enter n:"); scanf("%d",&n); for(i=0;i<=n;i++){ power=pow(2,i); printf("pow(2,%d)=%.0f\n",i,power); } return 0; }
#include<stdio.h> double fact(int n); int main(void) { int i,n; double result; printf("Enter n:"); scanf("%d",&n); for(i=0;i<=n;i++){ result=fact(i); printf("%d!=%.0f\n",i,result); } return 0; } double fact(int n) { int i; double product; product=1; for(i=1;i<=n;i++){ product=product*i; } return product; }