C语言作业习题讲解.ppt

作业习题讲解 动态存储DynamicMemoryAllocation 申请内存函数malloc格式 void malloc unsignedsize 功能 申请长度为size字节的内存区返值 若申请成功 返回所分配的内存区首字节的地址 若申请失败 返回NULL说明 在实际申请内存时 要强制转换 例 申请长度为10的整型数组空间int p p int malloc 10 sizeof int 包含在头文件stdlib h 释放内存函数free格式 voidfree void p 功能 释放p所指的内存空间返值 无说明 p所指的内存区域必须是用函数malloc申请的 否则调用时可能会破坏系统 例 动态申请10个元素的整型数组 include includevoidassign inta intm intk for k 0 k m k a k k 10 for k 0 k m k printf d a k voidmain int p p int malloc 10 sizeof int printf nResult assign p 10 free p 第一次上机作业 1 1 大写字母转换成小写字母if c A c Z a A 32getchar putchar 1 2 求平方根math hsqrt scanf f x 2f 1 3 TemperatureConversionc 5 0 9 f 32 1 4 计算旅途时间 1 5 数字加密 第二次上机作业 2 1 4个数排序if语句t a a b b t 2 2 求1 1 2 1 n 嵌套for循环 2 3 编程计算表达式 data1opdata2的值 switch语句 2 4 用二分法求方程2x3 4x2 3x 6 0在 a b 之间的根double lfwhile 1 break for s 0 i 1 i n i for t 1 j 1 j i j t j s 1 t scanf d c d 2 5 cCalendarDisplay voidmain while 1 ComputedaysfromJan1 Inputvalidity 1 12 whatdayisfirstdayofthismonth Displaycalendarofthismonth while 1 printf Wouldyouliketocontinue y n fflush stdin ch getchar if ch N ch n break intdayinmonth 12 31 28 31 30 31 30 31 31 30 31 30 31 days 0 for i 0 i month 1 i days dayinmonth i intfday 1 thefirstdayof2007ismonday fday days fday 7 printf n printf SUNMONTUEWEDTHUFRISAT n for i 0 i fday i printf for i 1 i dayinmonth month 1 i if i fday 7 0 printf 7d n i elseprintf 7d i printf n 第三次上机作业 3 4 CountCapitalConsonantLetters charstr N MAXLEN for i 0 count 0 i A 3 1 BinarySearch 3 2 Sorting 3 5 Stringconnection welcometo 0 str1 c h i n a 0 c h i n a 0 gets str1 gets str2 for i 0 str1 i 0 i for j 0 str2 j 0 str1 i str2 j str1 i 0 puts str1 3 3 Statistics NOMTENPHSUMAVE 90 197879227692N292919027391Y390818225384N defineN30 defineM3ints N M 4 for i 0 i N i printf Inputnumber scanf d for i 0 i 90 count s i M 2 s i M 1 M if count M s i M 3 Y elses i M 3 N 3 6 c十六进制转换十进制 Pf4 1 0 str num f 4 1 0 3 6 c十六进制转换十进制 Pf4 1 0 str num f 4 1 0 for number 0 i 0 num i 0 i if num i A 3 7 矩阵运算 sum 0 for i 0 i n i for j 0 j n j if i n 1 j n 1 i j n 1 continue elsesum a i j 4 1 c数组转置 第四次上机作业 inta N N printf Inputn n 6 scanf d printf Displaythearray n for i 0 i n i for j 0 j n j printf 4d a i j printf n transpose a n voidtranspose inta N intn voidtranspose int a N intn 4 1 c数组转置 for i 0 i n i for j 0 j n j t a i j a i j a j i a j i t 1 5 9 13 2 3 4 i 0 第四次上机作业 6 10 14 7 8 4 1 c数组转置 for i 0 i n i for j 0 j n j t a i j a i j a j i a j i t 1 9 13 3 4 i 1 5 2 2 5 6 10 14 7 8 4 1 c数组转置 for i 0 i n i for j 0 j n j t a i j a i j a j i a j i t 1 9 13 3 4 i 2 5 2 2 5 3 9 7 10 11 12 15 6 10 14 7 8 4 1 c数组转置 for i 0 i n i for j 0 j n j t a i j a i j a j i a j i t 1 9 13 3 4 i 3 5 2 2 5 3 9 7 10 11 12 15 4 13 14 8 15 12 16 4 1 c数组转置 for i 0 i n i for j 0 j i j t a i j a i j a j i a j i t i 0 4 1 c数组转置 for i 0 i n i for j 0 j i j t a i j a i j a j i a j i t 5 2 i 1 4 1 c数组转置 for i 0 i n i for j 0 j i j t a i j a i j a j i a j i t 5 9 2 3 i 2 10 7 4 1 c数组转置 for i 0 i n i for j 0 j i j t a i j a i j a j i a j i t 5 9 13 2 3 4 i 3 10 7 14 8 15 12 4 2 学生信息 voidsort charname LEN floats inti j k floatt charstring LEN for i 0 is k k j if k i t s i s i s k s k t strcpy string name i strcpy name i name k strcpy name k string input sort display search voidmain intnum charname N LEN student LEN floatscore N input name score display name score sort name score display name score printf Inputstudentnameyouwanttosearch fflush stdin gets student num search name student if num 1 puts SearchFailure elseprintf s sscoreis 2f n student score num voidinput charname LEN floats inti printf Inputnameandscore n for i 0 i N i scanf s name i scanf f intsearch charname LEN chars inti for i 0 i N i if strcmp name i s 0 returni return 1 4 3 c字符串处理 SAMPLEOUTPUT 1 Reverseastring 2 Deleteacharacterinastring Pleaseinputyourchoice 1Enterastring holidayReversedstringis yadilohWouldyouliketocontinue y n Y1 Reverseastring 2 Deleteacharacterinastring Pleaseinputyourchoice 2Enterastring oneworld onedreamEnteracharacteryouwanttodelete oDeletedstringis newrld nedreamWouldyouliketocontinue y n N voidmain while 1 printf Wouldyouliketocontinue y n fflush stdin choice2 getchar if choice2 N choice2 n break printf 1 Reverseastring n printf 2 Deleteacharacterinastring n printf Pleaseinputyourchoice scanf d switch choice1 case1 break case2 break Reversethestring a k j b c i j 0 1 2 3 i 10 9 8 7 Algorithm whilej i exchangethecorrespondingcharacter for i 0 str i 0 i i for j 0 j i j i c str i str i str j str j c i strlen str i voidstrreverse chars Deleteacharacterinastring oneworld onedream 0 str c o n e w r l d n e d r e a m 0 voiddelchar chars charc Deleteacharacterinastring c o n e w r l d n e d r e a m 0 n e w r l d n e d r e a m 0 4 4 分别用函数和带参数的宏 从三个数中找出最大数 带参数的宏方式实现 include defineMAX a b c a b a b c a b a b cvoidmain inta b c printf Input3integers n scanf d d d 5 1 c数据移位有n n 10 个整数 使前面各数顺序向后移m m n 个位置 最后m个数变成最前面的m个数 如图所示 编写函数shift a n m 实现上述功能 在主函数中输入n个整数和输出调整后的n个数 第五次上机作业 n m n m n m n m n m n m n m n m n m n m n m n m 5 1 c数据移位有n n 10 个整数 使前面各数顺序向后移m m n 个位置 最后m个数变成最前面的m个数 如图所示 编写函数shift a n m 实现上述功能 在主函数中输入n个整数和输出调整后的n个数 include includevoidshift inta intn intm voidmain inti n m int a printf Inputn n 10 scanf d voidshift inta intn intm inti j t for i 0 i 0 j a j 1 a j a 0 t 5 2 c字符串排序在主函数中输入10个不等长的字符串放入二维字符数组中 编写函数sort 利用指针数组对其排序 在主函数中输出排好序的字符串 include include defineN10 defineM80voidsort char s voidmain chars N M strp N inti printf Input10strings n for i 0 i N i gets s i for i 0 i N i strp i s i sort strp printf Outputsortedstrings n for i 0 i N i puts strp i voidsort char s inti j k char p for i 0 i0 k j f i j p s k s k s i s i p 2 Darrayvs Pointerarrays chara 5 9 a 0 a 1 a 2 a 3 a 4 char a 5 a 0 a 1 a 2 a 3 a 4 5 2 c字符串排序在主函数中输入10个不等长的字符串放入二维字符数组中 编写函数sort 利用指针数组对其排序 在主函数中输出排好序的字符串 include include include defineM80voidsort char s intn voidmain char strp inti n printf Howmanystrings n scanf d voidsort char s intn inti j k char p for i 0 i0 k j f i j p s k s k s i s i p 5 3学生成绩统计 defineN30 defineM5ints N M 3 for i 0 i N i s i 0 i 1 printf d i 1 for j 1 j M j scanf d ave average s findfail s findgood s voidfindfail ints M 3 inti j count sum for i 0 i 2 s i M 2 N intaverage inta M 3 inti sum 0 for i 0 i N i sum a i 1 return sum N voidfindgood ints M 3 inti j count for i 0 i 85 count if count M s i M 1 90 s i M 2 Y 5 4 cMatrixMultiply 30 36 42 50 5 4 cMatrixMultiply 30 36 42 50 66 81 96 116 5 4 cMatrixMultiply 30 36 42 50 66 81 96 116 102 126 150 182 5 4 cMatrixMultiply 30 36 42 50 66 81 96 116 102 126 150 182 138 171 204 248 5 4 cMatrixMultiply 30 36 42 50 66 81 96 116 102 126 150 182 138 171 204 248 for i 0 i m i for j 0 j m j c i j 0 for k 0 k n k c i j a i k b k j 5 5 cCountKeywords IFheisill theni elseyouneedandgood IfheThenelseokandhellohowareandelse i f 0 1 5 5 cCountKeywords IFheisill theni elseyouneedandgood IfheThenelseokandhellohowareandelse h e 0 1 5 5 cCountKeywords IFheisill theni elseyouneedandgood IfheThenelseokandhellohowareandelse i s 0 1 5 5 cCountKeywords IFheisill theni elseyouneedandgood IfheThenelseokandhellohowareandelse i l l 1 0 5 5 cCountKeywords IFheisill theni elseyouneedandgood IfheThenelseokandhellohowareandelse t h e 1 n 0 1 5 5 cCountKeywords IFheisill theni elseyouneedandgood IfheThenelseokandhellohowareandelse 2 2 3 3 voidmain chartext LEN keys M N intn i num M 0 gets text scanf d voidcount char text charkeys N intn int num inti j k charwords N for i 0 text i 0 j 0 while text i text i text i i while text i 第六次上机作业 成绩处理定义一个结构体类型 从键盘输入20个学生的学号和数学 英语 计算机成绩 要求 1 计算并输出每一个学生三门课的平均成绩 2 计算并输出每门课程的平均成绩 3 查找并输出平均成绩最高的学生的记录 4 按平均成绩从高到低输出学生的成绩单 学号 数学 英语 计算机成绩和平均成绩 typedefstructstudent longnum floatscore M floataverage STU 第六次上机作业 成绩处理定义一个结构体类型 从键盘输入20个学生的学号和数学 英语 计算机成绩 要求 1 计算并输出每一个学生三门课的平均成绩 2 计算并输出每门课程的平均成绩 3 查找并输出平均成绩最高的学生的记录 4 按平均成绩从高到低输出学生的成绩单 学号 数学 英语 计算机成绩和平均成绩 文件将上面成绩处理程序中从键盘读入的学生原始数据保存到文件studata dat文件中 从文件中读入数据后 按平均成绩排序 并将排好序的数据保存到文件sorted dat中 typedefstructstudent longnum floatscore M floataverage STU voidmain intn i j STU s printf Pleaseinputthenumberofstudents n scanf d voidcalstuave intn STU s inti j for i 0 i n i s i average 0 for j 0 j M j s i average s i score j s i average M for i 0 i n i printf Number ldAverage 2f n s i num s i average voidcalcourseave intn STU s floatave M inti j for j 0 j M j ave j 0 for i 0 i n i ave j s i score j ave j n printf MathAverage 2f nEnglishAverage 2f nComputerAverage 2f n ave 0 ave 1 ave 2 voidfind intn STU s inti max 0 for i 1 is max average max i puts thehighestaveragestudentis n printf ld 2f 2f 2f 2f n s max num s max score 0 s max score 1 s max score 2 s max average voidsort intn STU s inti j k STUt for i 0 is k average k j if i k t s i s i s k s k t voidsave intn STU s char fname FILE fp inti if fp fopen fname wb NULL printf Fileopenerror n exit 0 fwrite voidload int n STU s char fname FILE fp inti if fp fop