2.2#includemain(){floatx=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)#includemain(){inta=12,b=3;floatx=18.5,y=4.6;printf("%f\n",(float)(a*b)/2);printf("%d\n",(int)x%(int)y);}3.1(2)#includemain(){intx=32,y=81,p,q;p=x++;q=--y;printf("%d%d\n",p,q);printf("%d%d\n",x,y);}3.2#includemain(){intx,b0,b1,b2,s;printf("Inputx:");scanf("%d",&x);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;1printf("s=%d\n",s);}3.3#include#includemain(){floatrate=0.0225;floatn,capital,deposit;printf("Inputn,capital:");scanf("%f,%f",&n,&capital);deposit=capital*pow(1+rate,n);printf("deposit=%f\n",deposit);}3.4#include#includemain(){floata,b,c;doublex,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);}习题44.1(1)#includemain(){charc1='a',c2='b',c3='c';printf("a%cb%cc%c\n",c1,c2,c3);}4.1(2)#includemain(){inta=12,b=15;printf("a=%d%%,b=%d%%\n",a,b);}24.1(3)#includemain(){inta,b;scanf("%2d%*2s%2d",&a,&b);printf("%d,%d\n",a,b);}4.2#includemain(){longa,b;floatx,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#includemain(){floata;printf("Inputa:");scanf("%f",&a);if(a>=0){a=a;printf("a=%f\n",a);}else{a=-a;printf("a=%f\n",a);}}5.2#includemain(){inta;printf("Inputa:");scanf("%d",&a);3if(a%2==0){printf("a是偶数");}else{printf("a是奇数");}}5.3#include#includemain(){floata,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#includemain(){floata,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);4}elseif(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#includemain(){intyear,flag;printf("Inputayear:");scanf("%d",&year);if(year%4==0&&year%400!=0||year%400==0){flag=1;}else{flag=0;}if(flag==1){printf("%disaleapyear!\n",year);}else{printf("%disnotaleapyear!\n",year);}}5.6#includemain(){intyear,flag;printf("Inputayear:");scanf("%d",&year);flag=year%400==0||year%4==0&&year%100!=0?1:0;if(flag==1&&flag!=0)5{printf("%disaleapyear!\n",year);}else{printf("%disnotaleapyear!\n",year);}}5.7#includemain(){charch;printf("Inputch:");scanf("%c",&ch);if(ch>='a'&&ch<='z'){ch=getchar();ch=ch-32;printf("%c,%d\n",ch,ch);}elseif(ch>='A'&&ch<='Z'){ch=getchar();ch=ch+32;printf("%c,%d\n",ch,ch);}else{printf("%c",ch);}}65.8#includemain(){charch;printf("Inputch:");scanf("%c",&ch);if(ch>=48&&ch<=57){printf("ch是数字字符\n");}elseif(ch>=65&&ch<=90){printf("ch是大写字母\n");}elseif(ch>=97&&ch<=122){printf("ch是小写字母\n");}elseif(ch==32){printf("ch是空格\n");}else{printf("ch是其他字符\n");}}5.9#includemain(){intscore,grade;printf("Inputscore:");scanf("%d",&score);grade=score/10;if(score<0||score>100){printf("Inputerror\n");}if(score>=90&&score<=100){printf("%d--A\n",score);}elseif(score>=80&&score<90){1pr...
