编辑代码

#include <iostream>
using namespace std;
void printArray(int array[], int arrLen) {
for (int i = 0; i < arrLen; ++i) {
cout << array[i] << " ";
}
cout << endl;
}
int binarySearchFirstEqual(int searchKey, int array[], int arrLen) {
int low = 0;
int high = arrLen - 1;
int keyPos = -1;
while (low <= high) {
int mid = low +((high - low + 1) >> 1);
if (array[mid] > searchKey) {
high = mid - 1;
}
else if (array[mid] < searchKey){
low = mid + 1;
}
else {
if (mid == 0 || array[mid - 1] != searchKey) {
keyPos = mid;
break;
}
else {
high = mid - 1;
}
}
}
return keyPos;
}
int binarySearchLastEqual(int searchKey, int array[], int arrLen) {
int low = 0;
int high = arrLen - 1;
int keyPos = -1;
while (low <= high) {
int mid = low +((high - low + 1) >> 1);
if (array[mid] > searchKey) {
high = mid - 1;
}
else if (array[mid] < searchKey){
low = mid + 1;
}
else {
if (mid == arrLen - 1 || array[mid + 1] != searchKey) {
keyPos = mid;
break;
}
else {
low = mid + 1;
}
}
}
return keyPos;
}
int binarySearchFirstLargerEqual(int searchKey, int array[], int arrLen) {
int low = 0;
int high = arrLen - 1;
int keyPos = -1;

while (low <= high) {
int mid = low +((high - low + 1) >> 1);
if (array[mid] >= searchKey) {
if (mid == 0 || array[mid - 1] < searchKey) {
keyPos = mid;
break;
}
else {
high = mid - 1;
}
}
else {
low = mid + 1;
}
}
return keyPos;
}
int binarySearchLastSmallerEqual(int searchKey, int array[], int arrLen) {
int low = 0;
int high = arrLen - 1;
int keyPos = -1;
while (low <= high) {
int mid = low +((high - low + 1) >> 1);
if (array[mid] <= searchKey) {
if (mid == arrLen - 1 || array[mid + 1] > searchKey) {
keyPos = mid;
break;
}
else {
low = mid + 1;
}
}
else {
high = mid - 1;
}
}
return keyPos;
}
int main(){
int array0[] = {1, 1, 2, 3, 4, 5, 6};
int arrayLen = sizeof(array0)/sizeof(int);

printArray(array0, arrayLen);
cout << "First Array Pos of 1: "<< binarySearchFirstEqual(1, array0, arrayLen) << endl;
cout << "Last Array Pos of 1: "<< binarySearchLastEqual(1, array0, arrayLen) << endl;
cout << "First Larger Equal Array Pos o