c语言-C程序设计(第四版)谭浩强-课后习题答案第4章(共8页)

1、C程序设计(第四版)谭浩强_课后习题答案第4章第4章选择结构程序设计854.1选择结构和条件判断854.2用if语句实现选择结构874.2.1用if语句处理选择结构举例874.2.2if语句的一般形式 894.3关系运算符和关系表达式914.3.1关系运算符及其优先次序914.3.2关系表达式924.4逻辑运算符和逻辑表达式924.4.1逻辑运算符及其优先次序934.4.2逻辑表达式944.4.3逻辑型变量964.5条件运算符和条件表达式974.6选择结构的嵌套994.7用switch语句实现多分支选择结构1024.8选择结构程序综合举例105习题1114-4-1#include int ma

2、in() int a,b,c; printf(请输入三个整数:); scanf(%d,%d,%d,&a,&b,&c); if (ab) if (bc) printf(max=%dn,c); else printf(max=%dn,b); else if (ac) printf(max=%dn,c); else printf(max=%dn,a); return 0;4-4-2#include int main() int a,b,c,temp,max; printf(请输入三个整数:); scanf(%d,%d,%d,&a,&b,&c); temp=(ab)?a:b; /*将a和b中的大者存入

3、temp中*/ max=(tempc)?temp:c; /*将a和b中的大者与c比较,取最大者*/ printf(三个整数的最大数是%dn,max); return 0;4-5-2#include #include #define M 1000int main() int i,k; printf(请输入一个小于%d的整数i:,M); scanf(%d,&i); while (iM) printf(输入的数不符合要求，请重新输入一个小于%d的整数i:,M); scanf(%d,&i); k=sqrt(i); printf(%d的平方根的整数部分是：%dn,i,k); return 0;4-5#i

4、nclude #include #define M 1000int main() int i,k; printf(请输入一个小于%d的整数i:,M); scanf(%d,&i); if (iM) printf(输入的数不符合要求，请重新输入一个小于%d的整数i:,M); scanf(%d,&i); k=sqrt(i); printf(%d的平方根的整数部分是：%dn,i,k); return 0;4-6.#include int main() int x,y; printf(输入x:); scanf(%d,&x); if(x1) /* x1 */ y=x; printf(x=%3d, y=x=

5、%dn ,x,y); else if(x10) /* 1=x=10 */ y=3*x-11; printf(x=%d, y=3*x-11=%dn,x,y); return 0;4-7-1#include int main() int x,y; printf(enter x:); scanf(%d,&x); y=-1; if(x!=0) if(x0) y=1; else y=0; printf(x=%d,y=%dn,x,y); return 0;4-7-2#include int main() int x,y; printf(please enter x:); scanf(%d,&x); y=0

6、; if(x=0) if(x0) y=1; else y=-1; printf(x=%d,y=%dn,x,y); return 0;4-8#include int main() float score; char grade; printf(请输入学生成绩:); scanf(%f,&score); while (score100|score0)printf(n 输入有误,请重输);scanf(%f,&score); switch(int)(score/10) case 10:case 9: grade=A;break;case 8: grade=B;break;case 7: grade=C;

7、break;case 6: grade=D;break;case 5:case 4:case 3:case 2:case 1:case 0: grade=E; printf(成绩是 %5.1f,相应的等级是%cn ,score,grade);return 0;4-9#include #include int main() int num,indiv,ten,hundred,thousand,ten_thousand,place; /分别代表个位,十位,百位,千位,万位和位数 printf(请输入一个整数(0-99999):); scanf(%d,&num); if (num9999) plac

8、e=5; else if (num999) place=4; else if (num99) place=3; else if (num9) place=2; else place=1; printf(位数:%dn,place); printf(每位数字为:); ten_thousand=num/10000; thousand=(int)(num-ten_thousand*10000)/1000; hundred=(int)(num-ten_thousand*10000-thousand*1000)/100; ten=(int)(num-ten_thousand*10000-thousand*

9、1000-hundred*100)/10; indiv=(int)(num-ten_thousand*10000-thousand*1000-hundred*100-ten*10); switch(place) case 5:printf(%d,%d,%d,%d,%d,ten_thousand,thousand,hundred,ten,indiv); printf(n反序数字为:); printf(%d%d%d%d%dn,indiv,ten,hundred,thousand,ten_thousand); break; case 4:printf(%d,%d,%d,%d,thousand,hun

10、dred,ten,indiv); printf(n反序数字为:); printf(%d%d%d%dn,indiv,ten,hundred,thousand); break; case 3:printf(%d,%d,%d,hundred,ten,indiv); printf(n反序数字为:); printf(%d%d%dn,indiv,ten,hundred); break; case 2:printf(%d,%d,ten,indiv); printf(n反序数字为:); printf(%d%dn,indiv,ten); break; case 1:printf(%d,indiv); print

11、f(n反序数字为:); printf(%dn,indiv); break; return 0; 4-10-1#include int main() int i; double bonus,bon1,bon2,bon4,bon6,bon10; bon1=100000*0.1; bon2=bon1+100000*0.075; bon4=bon2+100000*0.05; bon6=bon4+100000*0.03; bon10=bon6+400000*0.015; printf(请输入利润i:); scanf(%d,&i); if (i=100000) bonus=i*0.1; else if (

12、i=200000) bonus=bon1+(i-100000)*0.075; else if (i=400000) bonus=bon2+(i-200000)*0.05; else if (i=600000) bonus=bon4+(i-400000)*0.03; else if (i=1000000) bonus=bon6+(i-600000)*0.015; else bonus=bon10+(i-1000000)*0.01; printf(奖金是: %10.2fn,bonus); return 0; 4-10-2#include int main() int i; double bonus

13、,bon1,bon2,bon4,bon6,bon10; int branch; bon1=100000*0.1; bon2=bon1+100000*0.075; bon4=bon2+200000*0.05; bon6=bon4+200000*0.03; bon10=bon6+400000*0.015; printf(请输入利润i:); scanf(%d,&i); branch=i/100000; if (branch10) branch=10; switch(branch) case 0:bonus=i*0.1;break; case 1:bonus=bon1+(i-100000)*0.075

14、;break; case 2: case 3: bonus=bon2+(i-200000)*0.05;break; case 4: case 5: bonus=bon4+(i-400000)*0.03;break; case 6: case 7: case 8: case 9: bonus=bon6+(i-600000)*0.015;break; case 10: bonus=bon10+(i-1000000)*0.01; printf(奖金是 %10.2fn,bonus); return 0; 4-11#include int main() int t,a,b,c,d; printf(请输入

15、四个数:); scanf(%d,%d,%d,%d,&a,&b,&c,&d); printf(a=%d,b=%d,c=%d,d=%dn,a,b,c,d); if (ab) t=a;a=b;b=t; if (ac) t=a;a=c;c=t; if (ad) t=a;a=d;d=t; if (bc) t=b;b=c;c=t; if (bd) t=b;b=d;d=t; if (cd) t=c;c=d;d=t; printf(排序结果如下: n); printf(%d %d %d %d n ,a,b,c,d); return 0; 4-12#include int main() int h=10; float x1=2,y1=2,x2=-2,y2=2,x3=-2,y3=-2,x4=2,y4=-2,x,y,d1,d2,d3,d4; printf(请输入一个点(x,y):);