IOS面试大全之常见算法

int main(int argc, char *argv[]) {  int array[10] = {24, 17, 85, 13, 9, 54, 76, 45, 5, 63};  int num = sizeof(array)/sizeof(int);  for(int i = 0; i < num-1; i++) {    for(int j = 0; j < num - 1 - i; j++) {      if(array[j] < array[j+1]) {        int tmp = array[j];        array[j] = array[j+1];        array[j+1] = tmp;      }    }  }  for(int i = 0; i < num; i++) {    printf("%d", array[i]);    if(i == num-1) {      printf("/n");    }    else {      printf(" ");    }  }}

void sort(int a[],int n){  int i, j, index;  for(i = 0; i < n - 1; i++) {    index = i;    for(j = i + 1; j < n; j++) {      if(a[index] > a[j]) {        index = j;      }    }    if(index != i) {      int temp = a[i];      a[i] = a[index];      a[index] = temp;    }  }}int main(int argc, const char * argv[]) {  int numArr[10] = {86, 37, 56, 29, 92, 73, 15, 63, 30, 8};  sort(numArr, 10);  for (int i = 0; i < 10; i++) {    printf("%d, ", numArr[i]);  }  printf("/n");  return 0;}

void sort(int *a, int left, int right) {if(left >= right) {return ;}int i = left;int j = right;int key = a[left];while (i < j) {while (i < j && key >= a[j]) {j--;}a[i] = a[j];while (i < j && key <= a[i]) {  i++;}a[j] = a[i];}a[i] = key;sort(a, left, i-1);sort(a, i+1, right);}

void merge(int sourceArr[], int tempArr[], int startIndex, int midIndex, int endIndex) {  int i = startIndex;  int j = midIndex + 1;  int k = startIndex;  while (i != midIndex + 1 && j != endIndex + 1) {    if (sourceArr[i] >= sourceArr[j]) {      tempArr[k++] = sourceArr[j++];    } else {      tempArr[k++] = sourceArr[i++];    }  }  while (i != midIndex + 1) {    tempArr[k++] = sourceArr[i++];  }  while (j != endIndex + 1) {    tempArr[k++] = sourceArr[j++];  }  for (i = startIndex; i <= endIndex; i++) {    sourceArr[i] = tempArr[i];  }}void sort(int souceArr[], int tempArr[], int startIndex, int endIndex) {  int midIndex;  if (startIndex < endIndex) {    midIndex = (startIndex + endIndex) / 2;    sort(souceArr, tempArr, startIndex, midIndex);    sort(souceArr, tempArr, midIndex + 1, endIndex);    merge(souceArr, tempArr, startIndex, midIndex, endIndex);  }}int main(int argc, const char * argv[]) {  int numArr[10] = {86, 37, 56, 29, 92, 73, 15, 63, 30, 8};  int tempArr[10];  sort(numArr, tempArr, 0, 9);  for (int i = 0; i < 10; i++) {    printf("%d, ", numArr[i]);  }  printf("/n");  return 0;}

int bsearchWithoutRecursion(int array[],int low,int high,int target) {while(low <= high) {int mid = (low + high) / 2;if(array[mid] > target)high = mid - 1;else if(array[mid] < target)low = mid + 1;else  //findthetargetreturn mid;}//the array does not contain the targetreturn -1;}----------------------------------------递归实现int binary_search(const int arr[],int low,int high,int key){int mid=low + (high - low) / 2;if(low > high)return -1;else{if(arr[mid] == key)return mid;else if(arr[mid] > key)return binary_search(arr, low, mid-1, key);elsereturn binary_search(arr, mid+1, high, key);}}

#include <stdio.h>#include <stdlib.h>typedef struct NODE {  struct NODE *next;  int num;}node;node *createLinkList(int length) {  if (length <= 0) {    return NULL;  }  node *head,*p,*q;  int number = 1;  head = (node *)malloc(sizeof(node));  head->num = 1;  head->next = head;  p = q = head;  while (++number <= length) {    p = (node *)malloc(sizeof(node));    p->num = number;    p->next = NULL;    q->next = p;    q = p;  }  return head;}void printLinkList(node *head) {  if (head == NULL) {    return;  }  node *p = head;  while (p) {    printf("%d ", p->num);    p = p -> next;  }  printf("/n");}node *reverseFunc1(node *head) {  if (head == NULL) {    return head;  }  node *p,*q;  p = head;  q = NULL;  while (p) {    node *pNext = p -> next;    p -> next = q;    q = p;    p = pNext;  }  return q;}int main(int argc, const char * argv[]) {  node *head = createLinkList(7);  if (head) {    printLinkList(head);    node *reHead = reverseFunc1(head);    printLinkList(reHead);    free(reHead);  }  free(head);  return 0;}

int spliterFunc(char *p) {  char c[100][100];  int i = 0;  int j = 0;  while (*p != '/0') {    if (*p == ' ') {      i++;      j = 0;    } else {      c[i][j] = *p;      j++;    }    p++;  }  for (int k = i; k >= 0; k--) {    printf("%s", c[k]);    if (k > 0) {      printf(" ");    } else {      printf("/n");    }  }  return 0;}

char *strOutPut(char *);int compareDifferentChar(char, char *);int main(int argc, const char * argv[]) {  char *inputStr = "abaccddeeef";  char *outputStr = strOutPut(inputStr);  printf("%c /n", *outputStr);  return 0;}char *strOutPut(char *s) {  char str[100];  char *p = s;  int index = 0;  while (*s != '/0') {    if (compareDifferentChar(*s, p) == 1) {      str[index] = *s;      index++;    }    s++;  }  return &str;}int compareDifferentChar(char c, char *s) {  int i = 0;  while (*s != '/0' && i<= 1) {    if (*s == c) {      i++;    }    s++;  }  if (i == 1) {    return 1;  } else {    return 0;  }}

ADECBHGF

int main(int argc, const char * argv[]) {  for (int i = 2; i < 100; i++) {    int r = isPrime(i);    if (r == 1) {      printf("%ld ", i);    }  }  return 0;}int isPrime(int n){  int i, s;  for(i = 2; i <= sqrt(n); i++)    if(n % i == 0) return 0;  return 1;}

int gcd(int a, int b) {  int temp = 0;  if (a < b) {    temp = a;    a = b;    b = temp;  }  while (b != 0) {    temp = a % b;    a = b;    b = temp;  }  return a;}