1、12.2 #includemain()float x=2.5,y=2.5,z=2.5;printf(“x=%fn“,x);printf(“y=%fn“,y);printf(“z=%fn“,z);3.1(1) #includemain()int a=12,b=3;float x=18.5,y=4.6;printf(“%fn“,(float)(a*b)/2);printf(“%dn“,(int)x%(int)y);3.1(2)#includemain()int x=32,y=81,p,q;p=x+;q=-y;printf(“%d %dn“,p,q);printf(“%d %dn“,x,y);3.2
2、 #includemain()int x,b0,b1,b2,s;printf(“Inputx:“);scanf(“%d“,b2=x/100;b1=(x-b2*100)/10;/或(x%100)/10; 或 x/10%10;b0=x%10;s=b0*100+b1*10+b2;2printf(“s=%dn“,s);3.3 #include#includemain()float rate=0.0225;float n,capital,deposit;printf(“Input n,capital:“);scanf(“%f,%f“,deposit=capital*pow(1+rate,n);print
3、f(“deposit=%fn“,deposit);3.4 #include#includemain()float a, b, c;double x, y;printf(“Input a, b, c:“);scanf(“%f %f %f“, x=(-b+sqrt(b*b-4*a*c)/(2*a);y=(-b-sqrt(b*b-4*a*c)/(2*a);printf(“x=%f,y=%fn“,x,y);习题 44.1(1) #includemain()char c1=a,c2=b,c3=c;printf(“a%cb%cc%cn“,c1,c2,c3);4.1(2) #includemain()int
4、 a=12,b=15;printf(“a=%d%,b=%d%n“,a,b);34.1(3) #includemain()int a,b;scanf(“%2d%*2s%2d“,printf(“%d,%dn“,a,b);4.2 #includemain()long a,b;float x,y;scanf(“%d,%dn“,scanf(“%f,%fn“,printf(“a=%d,b=%dn“,a,b);printf(“x=%f,b=%fn“,x,y);5.1 #includemain()float a;printf(“Input a:“);scanf(“%f“,if(a=0)a=a;printf(“
5、a=%fn“,a);elsea=-a;printf(“a=%fn“,a);5.2 #includemain()int a;printf(“Input a:“);scanf(“%d“, 4if(a%2=0)printf(“a 是偶数“);elseprintf(“a 是奇数“);5.3 #include#includemain()float a,b,c,s,area;printf(“Input a, b, c:“);scanf(“%f %f %f“, if(a+bcarea=(float)sqrt(s*(s-a)*(s-b)*(s-c);printf(“area=%fn“,area);elsepr
6、intf(“不是三角形“);5.4 #include#includemain()float a,b,c,x,y;printf(“Inputa,b,c:“);scanf(“%f,%f,%f“,if(a=0)printf(“该方程不是一元二次方程 n“);if(b*b-4*a*c0)x=(-b+sqrt(b*b-4*a*c)/(2*a);y=(-b-sqrt(b*b-4*a*c)/(2*a);printf(“x=%f,y=%fn“,x,y);5else if(b*b-4*a*c=0)x=-b/(2*a);y=-b/(2*a);printf(“x=%f,y=%fn“,x,y);elseprintf(
7、“该方程无实根n“);5.5 #includemain()int year,flag;printf(“Input a year:“);scanf(“%d“,if(year%4=0elseflag=0;if(flag=1)printf(“%d is a leap year !n“,year);elseprintf(“%d is not a leap year !n“,year);5.6 #includemain()int year,flag;printf(“Input a year:“);scanf(“%d“,flag=year%400=0|year%4=0if(flag=1elseprintf
8、(“%d is not a leap year !n“,year);5.7 #includemain()char ch;printf(“Inputch:“);scanf(“%c“,if(ch=aprintf(“Inputch:“);scanf(“%c“,if(ch=48printf(“Input score:“);scanf(“%d“,grade=score/10;if(score100)printf(“Input errorn“);if(score=90printf(“Input year,month:“);scanf(“%d,%d“,if(month12|monthmain()int i,j,k;char space= ;for(i=1;imain()int k=4,n;for(n=0;nmain()int k=4,n;for(n=0;nmain()int i,sum=0;for(i=1;imain()long i;long term,sum=0;for(i=1;i#includemain()int n=1;float term=1.0,sign=1,sum=0;while(term=1e-4)term=1.0/sign;sum=sum+term;sign=sign+n;
