#include <stdio.h>
int main()
{void swap(int *p1, int *p2);int n1, n2, n3;int *p1, *p2, *p3;printf("input three integer n1,n2,n3:");scanf("%d,%d,%d", &n1, &n2, &n3);p1 = &n1;p2 = &n2;p3 = &n3;if (n1 > n2) swap(p1, p2);if (n1 > n3) swap(p1, p3);if (n2 > n3) swap(p2, p3);printf("Now,the order is:%d,%d,%d\n", n1, n2, n3);return 0;
}void swap(int *p1, int *p2)
{int p;p = *p1; *p1 = *p2; *p2 = p;
}
#include <stdio.h>
#include <string.h>
int main()
{void swap(char *, char *);char str1[20], str2[20], str3[20];printf("input three line:\n");gets(str1);gets(str2);gets(str3);if (strcmp(str1, str2) > 0) swap(str1, str2);if (strcmp(str1, str3) > 0) swap(str1, str3);if (strcmp(str2, str3) > 0) swap(str2, str3);printf("Now,the order is:\n");printf("%s\n%s\n%s\n", str1, str2, str3);return 0;
}void swap(char *p1, char *p2)
{char p[20];strcpy(p, p1); strcpy(p1, p2); strcpy(p2, p);
}
#include <stdio.h>
int main()
{void input(int *);void max_min_value(int *);void output(int *);int number[10];input(number);max_min_value(number);output(number);return 0;
}void input(int *number)
{int i;printf("input 10 numbers:");for (i = 0; i < 10; i++)scanf("%d", &number[i]);
}void max_min_value(int *number)
{int *max, *min, *p, temp;max = min = number;for (p = number + 1; p < number + 10; p++)if (*p > *max) max = p;else if (*p < *min) min = p;temp = number[0]; number[0] = *min; *min = temp;if (max == number) max = min;temp = number[9]; number[9] = *max; *max = temp;
}void output(int *number)
{int *p;printf("Now,they are: ");for (p = number; p < number + 10; p++)printf("%d ", *p);printf("\n");
}
#include <stdio.h>
int main()
{void move(int[20], int, int);int number[20], n, m, i;printf("how many numbers?");scanf("%d", &n);printf("input %d numbers:\n", n);for (i = 0; i < n; i++)scanf("%d", &number[i]);printf("how many place you want move?");scanf("%d", &m);move(number, n, m);printf("Now,they are:\n");for (i = 0; i < n; i++)printf("%d ", number[i]);printf("\n");return 0;
}void move(int array[20], int n, int m)
{int *p, array_end;array_end = *(array + n - 1);for (p = array + n - 1; p > array; p--)*p = *(p - 1);*array = array_end;m--;if (m > 0) move(array, n, m);
}
#include <stdio.h>
int main()
{int i, k, m, n, num[50], *p;printf("\ninput number of person: n=");scanf("%d", &n);p = num;for (i = 0; i < n; i++)*(p + i) = i + 1;i = 0;k = 0;m = 0;while (m < n - 1){if (*(p + i) != 0) k++;if (k == 3){*(p + i) = 0;k = 0;m++;}i++;if (i == n) i = 0;}while (*p == 0) p++;printf("The last one is NO.%d\n", *p);return 0;
}
#include <stdio.h>
int main()
{int length(char *p);int len;char str[20];printf("input string: ");scanf("%s", str);len = length(str);printf("The length of string is %d.\n", len);return 0;
}int length(char *p)
{int n;n = 0;while (*p != '\0'){n++;p++;}return(n);
}
#include <stdio.h>
#include <string.h>
int main()
{void copystr(char *, char *, int);int m;char str1[20], str2[20];printf("input string:");gets(str1);printf("which character that begin to copy?");scanf("%d", &m);if (strlen(str1) < m)printf("input error!");else{copystr(str1, str2, m);printf("result:%s\n", str2);}return 0;
}void copystr(char *p1, char *p2, int m)
{int n;n = 0;while (n < m - 1){n++;p1++;}while (*p1 != '\0'){*p2 = *p1;p1++;p2++;}*p2 = '\0';
}
#include <stdio.h>
int main()
{int upper = 0, lower = 0, digit = 0, space = 0, other = 0, i = 0;char *p, s[20];printf("input string: ");while ((s[i] = getchar()) != '\n') i++;p = &s[0];while (*p != '\n'){if (('A' <= *p) && (*p <= 'Z'))++upper;else if (('a' <= *p) && (*p <= 'z'))++lower;else if (*p == ' ')++space;else if ((*p <= '9') && (*p >= '0'))++digit;else++other;p++;}printf("upper case:%d lower case:%d", upper, lower);printf(" space:%d digit:%d other:%d\n", space, digit, other);return 0;
}
#include <stdio.h>
int main()
{void move(int *pointer);int a[3][3], *p, i;printf("input matrix:\n");for (i = 0; i < 3; i++)scanf("%d %d %d", &a[i][0], &a[i][1], &a[i][2]);p = &a[0][0];move(p);printf("Now,matrix:\n");for (i = 0; i < 3; i++)printf("%d %d %d\n", a[i][0], a[i][1], a[i][2]);return 0;
}void move(int *pointer)
{int i, j, t;for (i = 0; i < 3; i++)for (j = i; j < 3; j++){t = *(pointer + 3 * i + j);*(pointer + 3 * i + j) = *(pointer + 3 * j + i);*(pointer + 3 * j + i) = t;}
}
//8.10.1
#include <stdio.h>
int main()
{void change(int *p);int a[5][5], *p, i, j;printf("input matrix:\n");for (i = 0; i < 5; i++)for (j = 0; j < 5; j++)scanf("%d", &a[i][j]);p = &a[0][0];change(p);printf("Now,matrix:\n");for (i = 0; i < 5; i++){for (j = 0; j < 5; j++)printf("%d ", a[i][j]);printf("\n");}return 0;
}void change(int *p)
{int i, j, temp;int *pmax, *pmin;pmax = p;pmin = p;for (i = 0; i < 5; i++)for (j = i; j < 5; j++){if (*pmax < *(p + 5 * i + j)) pmax = p + 5 * i + j;if (*pmin > *(p + 5 * i + j)) pmin = p + 5 * i + j;}temp = *(p + 12);*(p + 12) = *pmax;*pmax = temp;temp = *p;*p = *pmin;*pmin = temp;pmin = p + 1;for (i = 0; i < 5; i++)for (j = 0; j < 5; j++)if (((p + 5 * i + j) != p) && (*pmin > *(p + 5 * i + j))) pmin = p + 5 * i + j;temp = *pmin;*pmin = *(p + 4);*(p + 4) = temp;pmin = p + 1;for (i = 0; i < 5; i++)for (j = 0; j < 5; j++)if (((p + 5 * i + j) != (p + 4)) && ((p + 5 * i + j) != p) && (*pmin > *(p + 5 * i + j)))pmin = p + 5 * i + j;temp = *pmin;*pmin = *(p + 20);*(p + 20) = temp;pmin = p + 1;for (i = 0; i < 5; i++)for (j = 0; j < 5; j++)if (((p + 5 * i + j) != p) && ((p + 5 * i + j) != (p + 4)) && ((p + 5 * i + j) != (p + 20)) && (*pmin > *(p + 5 * i + j)))pmin = p + 5 * i + j;temp = *pmin;*pmin = *(p + 24);*(p + 24) = temp;
}//8.10.2
#include <stdio.h>
int main()
{void change(int *p);int a[5][5], *p, i, j;printf("input matrix:\n");for (i = 0; i < 5; i++)for (j = 0; j < 5; j++)scanf("%d", &a[i][j]);p = &a[0][0];change(p);printf("Now,matrix:\n");for (i = 0; i < 5; i++){for (j = 0; j < 5; j++)printf("%d ", a[i][j]);printf("\n");}return 0;
}void change(int *p) //交换函数
{int i, j, temp;int *pmax, *pmin;pmax = p;pmin = p;for (i = 0; i < 5; i++) //找最大值和最小值的地址,并赋给 pmax,pminfor (j = i; j < 5; j++){if (*pmax < *(p + 5 * i + j)) pmax = p + 5 * i + j;if (*pmin > *(p + 5 * i + j)) pmin = p + 5 * i + j;}temp = *(p + 12); //将最大值与中心元素互换*(p + 12) = *pmax;*pmax = temp;temp = *p; //将最小值与左上角元素互换*p = *pmin;*pmin = temp;pmin = p + 1;//将a[0][1]的地址赋给pmin，从该位置开始找最小的元素for (i = 0; i < 5; i++) //找第二最小值的地址赋给 pmin for (j = 0; j < 5; j++){if (i == 0 && j == 0) continue;if (*pmin > *(p + 5 * i + j)) pmin = p + 5 * i + j;}temp = *pmin; //将第二最小值与右上角元素互换 *pmin = *(p + 4);*(p + 4) = temp;pmin = p + 1;for (i = 0; i < 5; i++) //找第三最小值的地址赋给pmin for (j = 0; j < 5; j++){if ((i == 0 && j == 0) || (i == 0 && j == 4)) continue;if (*pmin > *(p + 5 * i + j)) pmin = p + 5 * i + j;}temp = *pmin; //将第三最小值与左下角元素互换*pmin = *(p + 20);*(p + 20) = temp;pmin = p + 1;for (i = 0; i < 5; i++) //找第四最小值的地址赋给pmin for (j = 0; j < 5; j++){if ((i == 0 && j == 0) || (i == 0 && j == 4) || (i == 4 && j == 0)) continue;if (*pmin > *(p + 5 * i + j)) pmin = p + 5 * i + j;}temp = *pmin; //将第四最小值与右下角元素互换*pmin = *(p + 24);*(p + 24) = temp;
}
//8.11.1
#include <stdio.h>
#include <string.h>
int main()
{void sort(char s[][6]);int i;char str[10][6];printf("input 10 strings:\n");for (i = 0; i < 10; i++)scanf("%s", str[i]);sort(str);printf("Now,the sequence is:\n");for (i = 0; i < 10; i++)printf("%s\n", str[i]);return 0;
}void sort(char s[10][6])
{int i, j;char *p, temp[10];p = temp;for (i = 0; i < 9; i++)for (j = 0; j < 9 - i; j++)if (strcmp(s[j], s[j + 1]) > 0){strcpy(p, s[j]);strcpy(s[j], s[+j + 1]);strcpy(s[j + 1], p);}
}//8.11.2
#include <stdio.h>
#include <string.h>
int main()
{void sort(char(*p)[6]);int i;char str[10][6];char(*p)[6];printf("input 10 strings:\n");for (i = 0; i < 10; i++)scanf("%s", str[i]);p = str;sort(p);printf("Now,the sequence is:\n");for (i = 0; i < 10; i++)printf("%s\n", str[i]);return 0;
}void sort(char(*s)[6])
{int i, j;char temp[6], *t = temp;for (i = 0; i < 9; i++)for (j = 0; j < 9 - i; j++)if (strcmp(s[j], s[j + 1]) > 0){strcpy(t, s[j]);strcpy(s[j], s[+j + 1]);strcpy(s[j + 1], t);}
}
#include <stdio.h>
#include <string.h>
int main()
{void sort(char *[]);int i;char *p[10], str[10][20];for (i = 0; i < 10; i++)p[i] = str[i];printf("input 10 strings:\n");for (i = 0; i < 10; i++)scanf("%s", p[i]);sort(p);printf("Now,the sequence is:\n");for (i = 0; i < 10; i++)printf("%s\n", p[i]);return 0;
}void sort(char *s[])
{int i, j;char *temp;for (i = 0; i < 9; i++)for (j = 0; j < 9 - i; j++)if (strcmp(*(s + j), *(s + j + 1)) > 0){temp = *(s + j);*(s + j) = *(s + j + 1);*(s + j + 1) = temp;}
}
#include<stdio.h>
#include<math.h>
int main()
{float integral(float(*)(float), float, float, int);//对integarl函数的声明float fsin(float); //对fsin函数的声明float fcos(float); //对fcos函数的声明float fexp(float); //对fexp函数的声明float a1, b1, a2, b2, a3, b3, c, (*p)(float);int n = 20;printf("input a1,b1:");scanf("%f,%f", &a1, &b1);printf("input a2,b2:");scanf("%f,%f", &a2, &b2);printf("input a3,b3:");scanf("%f,%f", &a3, &b3);p = fsin;c = integral(p, a1, b1, n);printf("The integral of sin(x) is:%f\n", c);p = fcos;c = integral(p, a2, b2, n);printf("The integral of cos(x) is:%f\n", c);p = fexp;c = integral(p, a3, b3, n);printf("The integral of exp(x) is:%f\n", c);return 0;
}float integral(float(*p)(float), float a, float b, int n)
{int i;float x, h, s;h = (b - a) / n;x = a;s = 0;for (i = 1; i <= n; i++){x = x + h;s = s + (*p)(x)*h;}return(s);
}
float fsin(float x)
{return sin(x);
}
float fcos(float x)
{return cos(x);
}
float fexp(float x)
{return exp(x);
}
#include <stdio.h>
int main()
{void sort(char *p, int m);int i, n;char *p, num[20];printf("input n:");scanf("%d", &n);printf("please input these numbers:\n");for (i = 0; i < n; i++)scanf("%d", &num[i]);p = &num[0];sort(p, n);printf("Now,the sequence is:\n");for (i = 0; i < n; i++)printf("%d ", num[i]);printf("\n");return 0;
}void sort(char *p, int m) //将n个数逆序排列函数
{int i;char temp, *p1, *p2;for (i = 0; i < m / 2; i++){p1 = p + i;p2 = p + (m - 1 - i);temp = *p1;*p1 = *p2;*p2 = temp;}
}
#include <stdio.h>
int main()
{void avsco(float *, float *);void avcour1(char(*)[10], float *);void fali2(char course[5][10], int num[], float *pscore, float aver[4]);void good(char course[5][10], int num[4], float *pscore, float aver[4]);int i, j, *pnum, num[4];float score[4][5], aver[4], *pscore, *paver;char course[5][10], (*pcourse)[10];printf("input course:\n");pcourse = course;for (i = 0; i < 5; i++)scanf("%s", course[i]);printf("input NO. and scores:\n");printf("NO.");for (i = 0; i < 5; i++)printf(",%s", course[i]);printf("\n");pscore = &score[0][0];pnum = &num[0];for (i = 0; i < 4; i++){scanf("%d", pnum + i);for (j = 0; j < 5; j++)scanf("%f", pscore + 5 * i + j);}paver = &aver[0];printf("\n\n");avsco(pscore, paver); //求出每个学生的平均成绩 avcour1(pcourse, pscore); //求出第一门课的平均成绩 printf("\n\n");fali2(pcourse, pnum, pscore, paver); //找出2门课不及格的学生 printf("\n\n");good(pcourse, pnum, pscore, paver); //找出成绩好的学生 return 0;
}void avsco(float *pscore, float *paver) //求每个学生的平均成绩的函数
{int i, j;float sum, average;for (i = 0; i < 4; i++){sum = 0.0;for (j = 0; j < 5; j++)sum = sum + (*(pscore + 5 * i + j)); //累计每个学生的各科成绩average = sum / 5; //计算平均成绩*(paver + i) = average;}
}void avcour1(char(*pcourse)[10], float *pscore) //求第一课程的平均成绩的函数
{int i;float sum, average1;sum = 0.0;for (i = 0; i < 4; i++)sum = sum + (*(pscore + 5 * i)); //累计每个学生的得分average1 = sum / 4; //计算平均成绩printf("course 1:%s average score:%7.2f\n", *pcourse, average1);
}void fali2(char course[5][10], int num[], float *pscore, float aver[4])
//找两门以上课程不及格的学生的函数
{int i, j, k, labe1;printf(" ==========Student who is fail in two courses======= \n");printf("NO. ");for (i = 0; i < 5; i++)printf("%11s", course[i]);printf(" average\n");for (i = 0; i < 4; i++){labe1 = 0;for (j = 0; j < 5; j++)if (*(pscore + 5 * i + j) < 60.0) labe1++;if (labe1 >= 2){printf("%d", num[i]);for (k = 0; k < 5; k++)printf("%11.2f", *(pscore + 5 * i + k));printf("%11.2f\n", aver[i]);}}
}void good(char course[5][10], int num[4], float *pscore, float aver[4])
//找成绩优秀学生(各门85以上或平均90分以上)的函数
{int i, j, k, n;printf(" ======Students whose score is good======\n");printf("NO. ");for (i = 0; i < 5; i++)printf("%11s", course[i]);printf(" average\n");for (i = 0; i < 4; i++){n = 0;for (j = 0; j < 5; j++)if (*(pscore + 5 * i + j) > 85.0) n++;if ((n == 5) || (aver[i] >= 90)){printf("%d", num[i]);for (k = 0; k < 5; k++)printf("%11.2f", *(pscore + 5 * i + k));printf("%11.2f\n", aver[i]);}}
}
#include <stdio.h>
int main()
{char str[50], *pstr;int i, j, k, m, e10, digit, ndigit, a[10], *pa;printf("input a string:\n");gets(str);pstr = &str[0]; //字符指针pstr置于数组str 首地址pa = &a[0]; //指针pa置于a数组首地址ndigit = 0; //ndigit代表有多少个整数i = 0; //代表字符串中的第几个字符j = 0;while (*(pstr + i) != '\0'){if ((*(pstr + i) >= '0') && (*(pstr + i) <= '9'))j++;else{if (j > 0){digit = *(pstr + i - 1) - 48; //将个数位赋予digitk = 1;while (k < j) //将含有两位以上数的其它位的数值累计于digit{e10 = 1;for (m = 1; m <= k; m++)e10 = e10 * 10; //e10代表该位数所应乘的因子digit = digit + (*(pstr + i - 1 - k) - 48)*e10; //将该位数的数值\累加于digitk++; //位数K自增}*pa = digit; //将数值赋予数组andigit++;pa++; //指针pa指向a数组下一元素j = 0;}}i++;}if (j > 0) //以数字结尾字符串的最后一个数据{digit = *(pstr + i - 1) - 48; //将个数位赋予digitk = 1;while (k < j) //将含有两位以上数的其它位的数值累加于digit{e10 = 1;for (m = 1; m <= k; m++)e10 = e10 * 10; //e10代表位数所应乘的因子digit = digit + (*(pstr + i - 1 - k) - 48)*e10; //将该位数的数值累加于digitk++; //位数K自增}*pa = digit; //将数值赋予数组andigit++;j = 0;}printf("There are %d numbers in this line, they are:\n", ndigit);j = 0;pa = &a[0];for (j = 0; j < ndigit; j++) //打印数据printf("%d ", *(pa + j));printf("\n");return 0;
}
#include<stdio.h>
int main()
{int strcmp(char *p1, char *p2);int m;char str1[20], str2[20], *p1, *p2;printf("input two strings:\n");scanf("%s", str1);scanf("%s", str2);p1 = &str1[0];p2 = &str2[0];m = strcmp(p1, p2);printf("result:%d,\n", m);return 0;
}int strcmp(char *p1, char *p2) //两个字符串比较函数
{int i;i = 0;while (*(p1 + i) == *(p2 + i))if (*(p1 + i++) == '\0') return(0); //相等时返回结果0 return(*(p1 + i) - *(p2 + i)); //不等时返回结果为第一个不等字符ASCII码的差值
}
#include <stdio.h>
int main()
{char *month_name[13] = { "illegal month","January","February","March","April","May","June","july","August","September","October", "November","December" };int n;printf("input month:\n");scanf("%d", &n);if ((n <= 12) && (n >= 1))printf("It is %s.\n", *(month_name + n));elseprintf("It is wrong.\n");return 0;
}
//8.19.1
#include <stdio.h>
#define NEWSIZE 1000 //指定开辟存区的最大容量
char newbuf[NEWSIZE]; //定义字符数组newbuf
char *newp = newbuf; //定义指针变量newp，指向可存区的始端 char *new(int n) //定义开辟存区的函数new,开辟存储区后返回指针
{ if (newp + n <= newbuf + NEWSIZE) //开辟区未超过newbuf数组的大小{newp += n; //newp指向存储区的末尾return(newp - n); //返回一个指针,它指向存区的开始位置}elsereturn(NULL); //当存区不够分配时,返回一个空指针
}//8.19.2
#include <stdio.h>
#define NEWSIZE 1000
char newbuf[NEWSIZE];
char *newp = newbuf;void free(char *p) //释放存区函数
{if (p >= newbuf && p < newbuf + NEWSIZE)newp = p;
}
#define LINEMAX 20 //定义字符串的最大长度
int main()
{int i;char **p, *pstr[5], str[5][LINEMAX];for (i = 0; i < 5; i++)pstr[i] = str[i]; //将第i个字符串的首地址赋予指针数组 pstr 的第i个元素printf("input 5 strings:\n");for (i = 0; i < 5; i++)scanf("%s", pstr[i]);p = pstr;sort(p);printf("strings sorted:\n");for (i = 0; i < 5; i++)printf("%s\n", pstr[i]);
}sort(char **p) //冒泡法对5个字符串排序函数
{int i, j;char *temp;for (i = 0; i < 5; i++){for (j = i + 1; j < 5; j++){if (strcmp(*(p + i), *(p + j)) > 0) //比较后交换字符串地址{temp = *(p + i);*(p + i) = *(p + j);*(p + j) = temp;}}}return 0;
}
#include<stdio.h>
int main()
{void sort(int **p, int n);int i, n, data[20], **p, *pstr[20];printf("input n:\n");scanf("%d", &n);for (i = 0; i < n; i++)pstr[i] = &data[i]; //将第i个整数的地址赋予指针数组 pstr 的第i个元素 printf("input %d integer numbers:", n);for (i = 0; i < n; i++)scanf("%d", pstr[i]);p = pstr;sort(p, n);printf("Now,the sequence is:\n");for (i = 0; i < n; i++)printf("%d ", *pstr[i]);printf("\n");return 0;
}
void sort(int **p, int n)
{int i, j, *temp;for (i = 0; i < n - 1; i++){for (j = i + 1; j < n; j++){if (**(p + i) > **(p + j)) //比较后交换整数地址 {temp = *(p + i);*(p + i) = *(p + j);*(p + j) = temp;}}}
}
