C语言作业及答案第一章：习题1.51.6第三章：习题3.63.9第四章：课本例题4.114.12写一遍第五章：习题5.55.6及课本例5.2写一遍第六章：习题6.26.3第七章：习题7.2或课本例题7.3写一遍1.5#include<stdio.h>voidmain(){printf("*********************************\n");printf("Verygood!\n");printf("*********************************\n");}1.6#include<stdio.h>voidmain(){floatmax(floatx,floaty,floatz);floata,b,c;printf("请分别输入a,b,c:\n");scanf("%f,%f,%f",&a,&b,&c);printf("max=%f",max(a,b,c));}floatmax(floatx,floaty,floatz){floatm,n;m=x>y?x:y;n=m>z?m:z;return(n);}3.6#include<stdio.h>voidmain(){charc1=’a’,c2=’b’,c3=’c’,c4=’\101’,c5=’\116’;printf(“a%cb%c\tc%c\tabc\n”,c1,c2,c3);printf(“\t\b%c%c\n”,c4,c5);}3.9.13.9.25.5#include<stdio.h>voidmain(){floatx,y;printf("请输入x的值：\n");scanf("%f",&x);if(x<1)y=x;elseif(x>=1&&x<10)y=2*x-1;elsey=3*x-11;printf("x与y的值分别为：\n%f,%f",x,y);printf("\n");}5.6#include<stdio.h>voidmain(){floatb;inta;printf("请输入该同学的成绩：\n");scanf("%f",&b);while(b<0||b>100){printf("输入有误，请重新输入：\n");scanf("%f",&b);}a=int(b/10);if(a<6)a=5;switch(a){case10:case9:printf("该同学为等级：A");break;case8:printf("该同学为等级：B");break;case7:printf("该同学为等级：C");break;case6:printf("该同学为等级：D");break;case5:printf("该同学为等级：E");break;}}6.2题目：输入一行字符，分别统计出其中英文字母、空格、数字和其他字符的个数。#include<stdio.h>voidmain(){inti=0,j=0,k=0,x=0;charc;printf("请输入一行字符串：\n");while((c=getchar())!='\n'){if(c>='A'&&c<='Z'||c>='a'&&c<='z')i++;elseif(c=='')j++;elseif(c>='0'&&c<='9')k++;elsex++;}printf("英文字母、空格、数字、其他字符的个数分别为：%d,%d,%d,%d,",i,j,k,x);printf("\n");}6.3求Sn=a+aa+aaa+…+aa…a之值，其中a是一个数字。例如：2＋22＋222＋2222＋22222（此时n＝5），n由键盘输入。#include<stdio.h>#include<math.h>voidmain(){inti,n;intsum=0,s=0;printf("请输入n的值：\n");scanf("%d",&n);while(n<1){printf("请重新输入n的值：\n");scanf("%d",&n);}for(i=0;i<n;i++){s+=pow(10,i);sum+=2*s;}printf("sum=%d\n",sum);}7.2#include<stdio.h>voidmain(){inti,j,t,a[10];printf("请输入十个整数：\n");for(i=0;i<10;i++){scanf("%d",&a[i