大学c 习题答案c 第七单元

1#include /sy0701.cppvoid main( ) int i,j,n,a3; / i: a2a1a0 三位数 for(i=100; i1000; i+) /对所有三位数循环for(n=i, j=0; j3; j+) /分解,这儿i不能改变aj=n%10; n/=10; for(n=0, j=0; j3; j+) /求三位数字平方和n+=aj*aj; if( (i/11=n) & (a0=a1 | a1=a2 | a0=a2) ) cout i n ; 2#include /sy0702.cppvoid main( ) char h16=0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F;int c20,n,i;coutn;for(i=0; n; i+) /循环结束后，i 是数的位数ci=n%16; n/=16; / i位的数存放在 ci-1,c1,c0 中for(i-;i=0;i-) /注意输出顺序cout hci;cout endl;2-1#include /sy0702_1.cpp 用函数实现int DtoH(int n,int c)for(int i=0; n; i+) /循环结束后，i 是数的位数ci=n%16; n/=16; / i位的数存放在 ci-1,c1,c0 中return i-1; /多加了一次，所以要减1void main( ) char h16=0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F;int c20,n,i;coutn;i=DtoH(n,c);for(;i=0;i-) cout hci;cout endl;3#include /sy0703.cppvoid input(int a, int n) /输入cout 请输入 n 个数:endl;for(int i=0; i ai;void sort(int a, int n) /用选择法排序，升序int i, j, t, k;for (i=0; in-1; i+) k=i; for (j=i+1; jn; j+)if(ajak) k=j; if(k!=i)t=ak;ak=ai; ai=t;void output( int a, int n ) /输出for(int i=0; in; i+)cout ai t;cout endl;void main( )int a50, n;cout n;input(a, n); sort(a, n); output(a, n);/*请输入数组元素个数:10请输入 10 个数:4534212345768987544 5 21 23 34 45 54 76 87 89*/4#include /sy0704.cpp 注意：要用实型数据处理void input(float a,int n)int i;cout请输入n个数:endl;for(i=0;iai;float aver(float a,int n)int i;float m=0;for(i=0;in;i+)m+=ai;m/=n;return m;float jfc(float a,int n)int i;float d=0,m;m=aver(a,n); for(i=0;in;i+)d+=(ai-m)*(ai-m);return d;void main()int n;float a100,d;coutn;input(a,n);d=jfc(a,n);cout均方差=dendl;/*请输入整数n的值:5请输入5个数:1.21.56.18.39.5均方差=58.528*/5#include int getbits(int n)int k=0;while(n!=0)k+;n/=10;return k;void split(int n,int a)int i=0;while (n!=0)ai+=n%10;n/=10;void sortd(int k,int a)int i,j,max,t;for(i=0;ik-1;i+)max=i;for(j=i+1;jk;j+)if(amaxaj) max=j;if(max!=i)t=ai; ai=amax; amax=t;void reverse(int k,int a)int i,t;for(i=0;ik/2;i+)t=ai; ai=ak-1-i; ak-1-i=t;int combine(int k,int a)int i,s=0;for(i=0;ik;i+)s=s*10+ai;return s;void main()int n,k,s1,s2,a4;cout请输入一个4位数或3位数n;k=getbits(n);dosplit(n,a);sortd(k,a);s1=combine(k,a);reverse(k,a);s2=combine(k,a);n=s1-s2;couts1 - s2 = nendl;while(n!=6174)&(n!=495);if (n=6174|n=495) coutOKn;/*请输入一个4位数或3位数32455432 - 2345 = 30878730 - 378 = 83528532 - 2358 = 6174OK*/*请输入一个4位数或3位数829982 - 289 = 693963 - 369 = 594954 - 459 = 495OK*/6-1#include int sum(int a 4)int i;int s=0;for(i=0; i4; i+)/一重循环s+=aii+ai3-i;return(s);void main( )int a44=1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16;cout 对角线和= sum(a) endl;/*对角线和=68*/6-2#include int sum(int a 4)int i, j;int s=0;for(i=0; i4; i+)/二重循环for(j=0; j4; j+)if( i=j | i+j=3 ) s+=aij;return(s);void main( )int a44=1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16;cout 对角线和= sum(a) endl;/*对角线和=68*/7#include /sy0707.cpp 矩阵转置#define N 4void main( )void rotate(int a N);int a N=1, 2, 3, 4,5, 6, 7, 8,9, 10, 11, 12,13, 14, 15, 16;int i, j;cout原始数组a:endl;for (i=0; iN; i+)for (j=0; jN; j+) coutaijt;coutn;rotate(a);cout转置过的数组 a:n;for (i=0; iN; i+)for(j=0; jN; j+) coutaijt;coutn;void rotate(int a N)int i,j,t;for (i=0; iN; i+)for (j=i+1; jN; j+) /注意j的初值不是0，对右上三角形内的元素循环t=aij;aij=aji;aji=t;/*原始数组a:1 2 3 45 6 7 89 10 11 1213 14 15 16转置过的数组 a:1 5 9 132 6 10 143 7 11 154 8 12 16*/8-1#include /sy0708.cpp 求学生成绩的平均分#define M 30#define N 2void main( )float courseMN=76,88,98,78,76,86,80,91,70,81, 76,98,88,77,90,91, 80,81,90,91,96,87,76,88,98,78,76,86,80,91,70,81, 76,98,88,77,80,81,90,91,96,87,76,88,98,78,76,86,80,91,70,81, 76,98,88,77,80,81,96,87 ; /给数组初初值，不须输入float course_averN=0,0, total_aver=0;int i, j;for(i=0; iM; i+)for(j=0; jN; j+)total_aver += courseij; course_averj += courseij; course_aver0/=M;course_aver1/=M;total_aver/=M*N;cout 全班两门课的总平均= total_aver endl;cout C+课程的平均分为 course_aver0 endl;cout 计算机应用基础课程的平均分为 course_aver1 endl;/* 全班两门课的总平均= 84.4 C+课程的平均分为 83 计算机应用基础课程的平均分为 85.8*/8-2#include /sy0708_1.cpp 求学生成绩的平均分 用函数处理#define M 30#define N 2float average(float courseN,float course_aver)int i, j;float total_aver=0;for(i=0; iM; i+)for(j=0; jN; j+)total_aver += courseij; course_averj += courseij; course_aver0/=M;course_aver1/=M;total_aver/=M*N;return total_aver;void main( )float courseMN=76,88,98,78,76,86,80,91,70,81, 76,98,88,77,90,91, 80,81,90,91,96,87,76,88,98,78,76,86,80,91,70,81, 76,98,88,77,80,81,90,91,96,87,76,88,98,78,76,86,80,91,70,81, 76,98,88,77,80,81,96,87 ; /给数组初初值，不须输入float course_averN=0,0, total_aver;total_aver=average(course,course_aver);cout 全班两门课的总平均= total_aver endl;cout C+课程的平均分为 course_aver0 endl;cout 计算机应用基础课程的平均分为 course_aver1 endl;/* 全班两门课的总平均= 84.4 C+课程的平均分为 83 计算机应用基础课程的平均分为 85.8*/9-1#include /此方法没有sy0709_1.cpp好#include void main( )char s200,s1200; int i=0, j=0;cout请输入一串字符:endl; cin.getline(s,200); /输入带空格的字符串 while(si!=0)if(si!= ) /将非空格复制到临时字符串s1中s1j+=si;i+; s1j=0; strcpy(s,s1); /再复制回去 coutsendl;/*请输入一串字符:asd fgh hg ddasdfghhgdd*/9-2#include void main( ) char s200; int i, j;cout请输入一串字符:endl; cin.getline(s, 200); /输入带空格的字符串for(i=j=0; si!=0; i+)if(si!= ) sj+=si; sj=0; coutsendl;9-3#include /用函数实现void delspace(char s)int i, j;for(i=j=0; si!=0; i+)if(si!= ) sj+=si; sj=0;void main( ) char s200; cout请输入一串字符:endl; cin.getline(s, 200); /输入带空格的字符串cout原始字符串为:sendl;delspace(s);cout删除空格后的字符串为:sendl;10-1#include #include void main( )char s200,t; int i,len;cout请输入一串字符:endl; cin.getline(s,200); cout原始字符串为: sendl;len=strlen(s);for(i=0;ilen/2;i+)t=si;si=slen-1-i;slen-1-i=t;cout逆转过的字符串为: sendl; /*请输入一串字符:aBcd fg原始字符串为: aBcd fg逆转过的字符串为: gf dcBa*/10-2#include /用函数实现#include void inverse(char s)int len;char t;len=strlen(s);for(int i=0;ilen/2;i+)t=si;si=slen-1-i;slen-1-i=t;void main( )char s200; cout请输入一串字符:endl; cin.getline(s,200); cout原始字符串为: sendl;inverse(s);cout逆转过的字符串为: sendl; /*请输入一串字符:aBcd fg原始字符串为: aBcd fg逆转过的字符串为: gf dcBa*/11#include /sy0711.cpp 实现字符串拷贝功能void my_strcpy(char s1,char s2)int i=0,j=0;while(s1j+=s2i+);void main( )char s1200,s2200; cout请输入一个字符串:endl; cin.getline(s2,200); my_strcpy(s1, s2); cout字符串s1为: s1endl; /*请输入一个字符串:aaa bbb vvv字符串s1为: aaa bbb vvv*/12#include /sy0712.cpp 实现字符串拼接功能void my_strcat(char s1,char s2)int i=0,j=0;while(s1j+);j-; /注意多加了一个1while(s2i) s1j+=s2i+;s1j=0;void main( )char s1200,s2200; cout请输入字符串1:endl; cin.getline(s1,200); cout请输入字符串2:endl; cin.getline(s2,200);my_strcat(s1, s2); cout拼接后的字符串s1为: s1endl; /*请输入字符串1:aaa请输入字符串2:bbb拼接后的字符串s1为: aaabbb*/13#include /li0713.cpp#define N 200void prime(int a)for(int i=1; iN-1;