C语言书后答案.doc

习题21. C2. A3. 2.024. x=6,y=7.z=-85. #define PI 3.1415926#includevoid main()double r,S,V;printf(请输入球体半径：);scanf(%lf,&r);S=4*PI*r*r;V=4./3*PI*r*r*r;printf(r=%10.2lf,S=%10.2lf,V=%10.2lfn,r,S,V);6.#include#includevoid main()double x1,y1,x2,y2,d;printf(请输入两点坐标x1,y1,x2,y2:);scanf(%lf,%lf,%lf,%lf,&x1,&y1,&x2,&y2);d=sqrt(x1-x2)*(x1-x2)+(y1-y2)*(y1-y2);printf(d=%10.2lf,d);7.#includevoid main()int a,x,y,z;printf(请输入一个三位数的正整数：);scanf(%i,&a);z=a%10;x=a/100;y=(a-x*100)/10;printf(百位数=%d,十位数=%d,个位数=%d,x,y,z);8.#includevoid main()char a,b,c;printf(请输入两个字符：);scanf(%c,%c,&a,&b); c=a;a=b;b=c;printf(a=%c,b=%c,a,b);习题四：基础部分：1#includevoid main()int i,sum=0;for(i=2;i=100;i+=2)sum=sum+i;printf(sum=%d,sum);2#includevoid main()int i,n;double sum=0;printf(请输入正整数n：);scanf(%d,&n);for(i=1;i=n;i+)sum=sum+1.0/i;printf(sum=%lf,sum);3#includevoid main()int i,n;double PI=1;printf(请输入正整数n：);scanf(%d,&n);for(i=1;i=n;i+)PI=PI*2.0*i*2*i/(2*i-1)/(2*i+1);PI=2*PI;printf(PI=%lf,PI);4.#includevoid main()int a,n,i,sum=0;printf(请输入正整数a，n：);scanf(%d %d,&a,&n);for (i=1;i=n;i+)sum=sum+a;a=a*10+a;printf(%dn,sum);5简便做法：#includevoid main()int x,y,z;for (z=1;z11;z+)for (y=1;y0 & 2*x+4*y+2*z=100)printf(鸡为%d只，狗为%d只，几头鸟为%d只。n,x,y,z);常规做法：#includevoid main()int x,y,z;for (x=1;x99;x+)for (y=1;y99;y+)for (z=1;z99;z+)if (2*x+4*y+2*z=100 & x+y+9*z=100)printf(%d %d %dn,x,y,z);6.#include#includevoid main()int m,i,k;for (m=100;m=200;m+)k=sqrt(m);for (i=2;i=k+1)printf(%dt,m);7.#includevoid main()char x;while(x=getchar()!=n) if(x57)printf(%c,x);8.#includevoid main()int a,b,c,x;for (x=100;x0 xfmin10.#include#includevoid main()int a,b,c,d,x;for (x=1000;x10000;x+)if (x=sqrt(x)*sqrt(x)a=x/1000;b=(x-a*1000)/100;c=(x-a*1000-b*100)/10;d=x%10;if(a+c=10&b*d=12)printf(%dt,x);11.C12i=5 j=4 k=613.beijing应用与提高部分：1.#includevoid main()int i,j,k,n,m;scanf(%d,&n);for(i=0;i=n;i+)for(j=0;jn-i;j+)printf( );for(k=0;ki+1;k+)printf(%c,65+k);for(m=0;mi;m+)printf(%c,63+k-m);printf(n);2#includevoid main()int x,y,r,s;scanf(%d%d,&x,&y);s=x*y;while (y!=0)r=x%y;x=y;y=r;s=s/x;printf(最小公倍数为%dn,s);3. #include#includevoid main()double a,x1,x2=0,s=0;scanf(%lf,&a);x1=a;dox2=1.0/2*(x1+a/x1);s=x2-x1;x1=x2;while(fabs(s)=1e-5);printf(%.2lf,x1);5.#includevoid main()float n,h,x,area=0,a=2.0,b=3.0,f1,f2;int i;scanf(%f,&n);h=(b-a)/n;x=a;f1=a*a;for(i=1;i=n;i+)x=x+h;f2=x*x;area=area+(f1+f2)/2*h;f1=f2;printf(%fn,area);习题五：1#includevoid main()int a10,i;printf(请输入10个整型数:n);for(i=0;i=0;i-)printf(%5d,ai);2#includevoid main()int a10,i,t;printf(请输入10个整型数:);for(i=0;i=9;i+)scanf(%d,&ai);for(i=0;i5;i+)t=a9-i;a9-i=ai;ai=t;for(i=0;i10;i+)printf(%6d,ai);3#includevoid main()float aver,sum=0.;int i,m=0,a20;printf(请输入20个学生的成绩:);for(i=0;i=19;i+)scanf(%d,&ai);for(i=0;i=19;i+)sum+=ai;aver=sum/20;for(i=0;i=19;i+)if(aiaver) m+;printf(平均分为%f,低于平均分的学生人数为%dn,aver,m);4#includevoid main()int i,j,a10,t,n;printf(请输入10个正整型数：);for(i=0;i10;i+)scanf(%d,&ai);printf(正整数n：);scanf(%d,&n);for(i=0;i10;i+)for(j=0;jaj+1)t=aj;aj=aj+1;aj+1=t;for(i=n;i10;i+)printf(%5d,ai);5#includevoid main()int i,j,a10,t;printf(input 10 numbers:n);for(i=0;i10;i+)scanf(%d,&ai);for(i=0;i9;i+)for(j=0;jaj+1)t=aj;aj=aj+1;aj+1=t;for(i=0;i10;i+)printf(%5d,ai);习题六：1#includeint abc(int x,int y)int r;while(y!=0)r=x%y;x=y;y=r;return x;void main()int a,b,s,x;scanf(%d%d,&a,&b);x=abc(a,b);s=a*b/x;printf(最小公倍数为：%d,s);2#includeint abc(int x)int a,b,c;a=x/100;c=x%10;b=(x-a*100)/10;if(x=a*a*a+b*b*b+c*c*c)return 1;elsereturn 0;void main()int x,i;scanf(%d,&x);i=abc(x);if(i)printf(是水仙花数);else printf(不是水仙花数);9#includeint Num(int n)if(n=1)return 6;else return Num(n-1)+3;void main()int n,x;scanf(%d,&n);x=Num(n);printf(%d,x);习题七：7.6：#includevoid main()char str20,*p;int i;gets(str);for(p=str;*p!=0;p+)if(*p=0 & *p=9)*p=42;p=str;for(i=0;i