《C语言程序设计》(苏小红) 课后习题答案 高等教育出版社

6.1(3) #include<stdio.h> main() { int k=4,n; for(n=0;n<k;n++) { if(n%2==0) break; k--; } printf("k=%d,n=%d\n",k,n); } 6.2(1) #include<stdio.h> main() { int i,sum=0; for(i=1;i<=101;i++) { sum=sum+i; } printf("sum=%d\n",sum); } 6.2(2) #include<stdio.h> main() { long i; long term,sum=0; for(i=1;i<=101;i=i+2) { term=i*(i+1)*(i+2); sum=sum+term; } printf("sum=%ld\n",sum); } 6.2(4) #include<stdio.h> #include<math.h> main() { int n=1; float term=1.0,sign=1,sum=0; while(term<=-1e-4||term>=1e-4) { term=1.0/sign; sum=sum+term; sign=sign+n;
main() { float a,b,c,x,y; printf("Inputa,b,c:"); scanf("%f,%f,%f",&a,&b,&c); if(a==0) { printf("该方程不是一元二次方程\n"); } if(b*b-4*a*c>0) { x=(-b+sqrt(b*b-4*a*c))/(2*a); y=(-b-sqrt(b*b-4*a*c))/(2*a); printf("x=%f,y=%f\n",x,y); } else if(b*b-4*a*c==0) { x=-b/(2*a); y=-b/(2*a); printf("x=%f,y=%f\n",x,y); } else { printf("该方程无实根\n"); } } 5.5 #include<stdio.h> main() { int year,flag; printf("Input a year:"); scanf("%d",&year); if(year%4==0&&year%400!=0||year%400==0) { flag=1; } else { flag=0; } if(flag==1) { printf("%d is a leap year !\n",year); }
5.8 #include<stdio.h> main() { char ch; printf("Inputch:"); scanf("%c",&ch); if(ch>=48&&ch<=57) { printf("ch 是数字字符\n"); } else if(ch>=65&&ch<=90) { printf("ch 是大写字母\n"); } else if(ch>=97&&ch<=122) { printf("ch 是小写字母\n"); } else if(ch==32) { printf("ch 是空格\n"); } else { printf("ch 是其他字符\n"); } } 5.9 #include<stdio.h> main() { int score,grade; printf("Input score:"); scanf("%d",&score); grade=score/10; if(score<0||score>100) { printf("Input error\n"); } if(score>=90&&score<=100) { printf("%d--A\n",score); } else if(score>=80&&score<90) {
n++; } printf("sum=%f\n",sum); } 6.2(5) #include<stdio.h> #include<math.h> main() { int n=1,count=1; float x; double sum,term; printf("Input x:"); scanf("%f",&x); sum=x; term=x; do{ term=-term*x*x/((n+1)*(n+2)); sum=sum+term; n=n+2; count++; }while(fabs(term)>=1e-5); printf("sin(x)=%f,count=%d\n",sum,count); } 6.3 #include<stdio.h> main() { int x=1,find=0; while(!find) { if(x%2==1&&x%3==2&&x%5==4&&x%6==5&&x%7==0) { printf("x=%d\n",x); find=1; x++; } } } /* int x,find=0; for (x=1;!find;x++) { if(x%2==1&&x%3==2&&x%5==4&&x%6==5&&x%7==0) { printf("x=%d\n",x); find=1;
printf("%d--B\n",score); } else if(score>=70&&score<80) { printf("%d--C\n",score); } else if(score>=60&&score<70) { printf("%d--D\n",score); } else if(score>=0&&score<60) { printf("%d- -E\n",score); } } 5.10 #include<stdio.h> main() { int year,month; printf("Input year,month:"); scanf("%d,%d",&year,&month); if(month>12||month<=0) { printf("error month\n"); } else { switch(year,month) { case 12: case 10: case 8: case 7: case 5: case 3: case 1: printf("31 天\n"); break; case 11: case 9: case 6: case 4: printf("30 天\n"); break;
case 2: if(year%4==0&&year!=0||year%400==0) { printf("29 天\n"); } else { printf("28 天\n"); } break; default: printf("Input error\n"); } } } 6.1(1) #include<stdio.h> main() { int i,j,k; char space=' '; for(i=1;i<=4;i++) { for(j=1;j<=i;j++) { printf("%c",space); } for(k=1;k<=6;k++) { printf("*"); } printf("\n"); } } 6.1(2) #include<stdio.h> main() { int k=4,n; for(n=0;n<k;n++) { if(n%2==0) continue; k--; } printf("k=%d\n,n=%d\n",k,n); }
else { printf("%d is not a leap year !\n",year); } } 5.6 #include<stdio.h> main() { int year,flag; printf("Input a year:"); scanf("%d",&year); flag=year%400==0||year%4==0&&year%100!=0?1:0; if(flag==1&&flag!=0) { printf("%d is a leap year !\n",year); } else { printf("%d is not a leap year !\n",year); } } 5.7 #include<stdio.h> main() { char ch; printf("Inputch:"); scanf("%c",&ch); if(ch>='a'&&ch<='z') { ch=getchar(); ch=ch-32; printf("%c,%d\n",ch,ch); } else if(ch>='A'&&ch<='Z') { ch=getchar(); ch=ch+32; printf("%c,%d\n",ch,ch); } else { printf("%c",ch); } }
double x,y; printf("Inputa,b,c:"); scanf("%f,%f,%f",&a,&b,&c); x=(-b+sqrt(b*b-4*a*c))/(2*a); y=(-b-sqrt(b*b-4*a*c))/(2*a); printf("x=%f,y=%f\n",x,y); } 4.1(1) #include<stdio.h> main() { char c1='a',c2='b',c3='c'; printf("a%cb%cc%c\n",c1,c2,c3); } 4.1(2) #include<stdio.h> main() { int a=12,b=15; printf("a=%d%%,b=%d%%\n",a,b); } 4.1(3) #include<stdio.h> main() { int a,b; scanf("%2d%*2s%2d",&a,&b); printf("%d,%d\n",a,b); } 4.2 #include<stdio.h> main() { long a,b; float x,y; scanf("%d,%d\n",&a,&b); scanf("%f,%f\n",&x,&y); printf("a=%d,b=%d\n",a,b); printf("x=%f,b=%f\n",x,y); } 5.1 #include<stdio.h> main() { float a; printf("Innputa:"); scanf("%f",&a); if(a>=0) {
2.2 #include<stdio.h> main() { float x=2.5,y=2.5,z=2.5; printf("x=%f\n",x); printf("y=%f\n",y); printf("z=%f\n",z); } 3.1(1) #include<stdio.h> main() { int a=12,b=3; float x=18.5,y=4.6; printf("%d\n",(float)(a*b)/2); printf("%d\n",(int)x%(int)y); } 3.2 #include<stdio.h> main() { int x,b0,b1,b2,s; printf(Baidu NhomakorabeaInputx:"); scanf("%d",&x); b2=x/100; b1=(x-b2*100)/10; b0=x%10; s=b0*100+b1*10+b2; printf("s=%d\n",s); } 3.3 #include<stdio.h> #include<math.h> main() { float rate=0.0225; float n,capital,deposit; printf("Input n,capital:"); scanf("%f,%f",&n,&capital); deposit=capital*pow(1+rate,n); printf("deposit=%f\n",deposit); } 3.4 #include<stdio.h> #include<math.h> main() { float a,b,c;
a=a; printf("a=%f\n",a); } else { a=-a; printf("a=%f\n",a); } } 5.2 #include<stdio.h> main() { int a; printf("Inputa:"); scanf("%d",&a); if(a%2==0) { printf("a 是偶数"); } else { printf("a 是奇数"); } } 5.3 #include<stdio.h> #include<math.h> main() { float a,b,c,s,area; printf("Inputa,b,c:"); scanf("%f,%f,%f",&a,&b,&c); if(a+b>c&&a+c>b&&b+c>a) { s=(a+b+c)/2; area=(float)sqrt(s*(s-a)*(s-b)*(s-c)); printf("area=%f\n",area); } else { printf("不是三角形"); } } 5.4 #include<stdio.h> #include<math.h>