ACM: binary search, and upper and lower bounds using the bipartite search

(1) binary template:

int binary_search(int *array, int length, int key) {int start = 0, end = length - 1;while(end >= start) {int middle = start + (end - start) / 2;int tmp = array[middle];if(tmp < key) start = middle + 1;else if (tmp > key) end = middle - 1;else return middle;}return -1;}

(2)

#include
 
  #includeint A[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11};int bsearch(int* A, int x, int y, int v) {  int m;  while(x < y) {    m = x+(y-x)/2;    if(A[m] == v) return m;    else if(A[m] > v) y = m;    else x = m+1;  }  return -1;}int main() {  int i;  for(i = 1; i <= 11; i++)    assert(bsearch(A, 0, 11, i) == i-1);  printf("Ok!\n");  return 0;}
 

(3) Finding the upper and lower bounds using the bipartite Method

#include
 
  #include#include 
  
   using namespace std;int A[] = {1, 2, 3, 3, 3, 3, 3, 5, 6};int lower_bound(int *array, int length, int v) {  int start = 0, end = length - 1;  while(start <= end) {    int middle = start + (end - start) / 2;    int tmp = array[middle];    if(array[middle] >= v) end = middle - 1;     else start = middle + 1;  }  return start;}int upper_bound(int *array, int length, int v) {  int start = 0, end = length-1;  while(start <= end) {    int middle = start + (end - start) / 2;    int tmp = array[middle];    if(array[middle] <= v) start = middle + 1;     else end = middle - 1;  }  return start;}int main() {  cout << lower_bound(A, 9, 3) << endl    << upper_bound(A, 9, 3) << endl;  return 0;}