一、概要
最近在看上學時候總結的一些東西，發現之前針對排序、字串、陣列、連結串列等，總結了一些面試時候常用的演算法程式碼，因此打算整理一下分享給大家。
本文介紹了排序演算法的C++程式碼實現，所有程式碼均可通過 菜鳥工具線上編譯器 直接執行，演算法目錄：
- 插入排序
- 希爾排序
- 選擇排序
- 氣泡排序
- 計數排序
- 基數排序
- 歸併排序
- 快速排序
- 雙向掃描的快速排序
- 堆排序
二、程式碼實現
2.1 插入排序
#include <iostream>
#include <stdexcept>
using namespace std;
void printArray(int *p, int length) {
for (int i = 0; i < length; i++) {
cout << p[i] << ", ";
}
}
void insertSort(int *p, int length){
if(p == NULL || length <= 0)
throw std::runtime_error("NULL Pointer");
int i,j,temp;
for(i = 1; i < length; i++){
temp = p[i];
for(j = i; j >= 1 && p[j-1] > temp; j--)
p[j] = p[j-1];
p[j] = temp;
}
}
int main()
{
int a[] = {30, 29, 50, 2, 42, 60};
insertSort(a, 6);
printArray(a, 6);
return 0;
}
複製程式碼執行結果：
>> 2, 29, 30, 42, 50, 60,
複製程式碼2.2 希爾排序
#include <iostream>
#include <stdexcept>
using namespace std;
void printArray(int *p, int length) {
for (int i = 0; i < length; i++) {
cout << p[i] << ", ";
}
}
void insertShell(int *p ,int inc, int length){
if(p == NULL || length <= 0 || inc <= 0 || inc >= length)
throw std::runtime_error("invaild input");
int i,j,temp;
for(i = inc; i < length; i++){
temp = p[i];
for(j = i; j >= inc && p[j-inc] > temp; j -= inc)
p[j] = p[j-inc];
p[j] = temp;
}
}
void shellSort(int *p, int length){
if(p == NULL || length <= 0)
throw std::runtime_error("invaild input");
int inc = length >> 1;
while(inc >= 1){
insertShell(p,inc,length);
inc >>= 1;
}
}
int main()
{
int a[] = {30, 29, 50, 2, 42, 60};
shellSort(a, 6);
printArray(a, 6);
return 0;
}
複製程式碼執行結果：
>> 2, 29, 30, 42, 50, 60,
複製程式碼2.3 選擇排序
#include <iostream>
#include <stdexcept>
using namespace std;
void printArray(int *p, int length) {
for (int i = 0; i < length; i++) {
cout << p[i] << ", ";
}
}
void selectSort(int *p, int length){
if(p == NULL || length <= 0)
throw std::runtime_error("NULL Pointer");
int i,j,mind,t;
for(j = 0; j < length - 1; j++){
mind = j;
for(i = j+1; i < length; i++){
if(p[i] < p[mind])
mind = i;
}
if(mind != j){
t = p[j]; p[j] = p[mind]; p[mind] = t;
}
}
}
int main()
{
int a[] = {30, 29, 50, 2, 42, 60};
selectSort(a, 6);
printArray(a, 6);
return 0;
}
複製程式碼執行結果：
>> 2, 29, 30, 42, 50, 60,
複製程式碼2.4 氣泡排序
#include <iostream>
#include <stdexcept>
using namespace std;
void printArray(int *p, int length) {
for (int i = 0; i < length; i++) {
cout << p[i] << ", ";
}
}
void bubbleSort(int *p, int length){
if(p == NULL || length <= 0)
throw std::runtime_error("NULL Pointer");
int i,j,t;
for(j = 0; j < length - 1; j++)
for(i = 0; i < length - j - 1; i++){
if(p[i] > p[i+1]){
t = p[i]; p[i] = p[i+1]; p[i+1] = t;
}
}
}
int main()
{
int a[] = {30, 29, 50, 2, 42, 60};
bubbleSort(a, 6);
printArray(a, 6);
return 0;
}
複製程式碼執行結果：
>> 2, 29, 30, 42, 50, 60,
複製程式碼2.5 計數排序
#include <iostream>
#include <stdexcept>
using namespace std;
void printArray(int *p, int length) {
for (int i = 0; i < length; i++) {
cout << p[i] << ", ";
}
}
void countSort(int *p, int length, int maxNum){
if(p == NULL || length <= 0 )
throw std::runtime_error("NULL Pointer");
int *c = new int[maxNum+1];
int *b = new int[length];
int i;
for(i = 0; i < maxNum+1; i++){
c[i] = 0;
}
for(i = 0; i < length; i++){
if(p[i] > maxNum)
throw std::runtime_error("invaild input");
c[p[i]] += 1;
}
for(i = 1; i < maxNum+1; i++){
c[i] += c[i-1];
}
for(i = length-1; i >= 0; i--){
if( c[p[i]] < 1 )
throw std::runtime_error("error");
b[--c[p[i]]] = p[i];
}
for(i = 0; i < length; i++)
p[i] = b[i];
delete [] c; c = NULL;
delete [] b; b = NULL;
}
int main()
{
int a[] = {30, 29, 50, 2, 42, 60};
countSort(a, 6, 60);
printArray(a, 6);
return 0;
}
複製程式碼執行結果為：
>> 2, 29, 30, 42, 50, 60,
複製程式碼2.6 基數排序
#include <iostream>
#include <stdexcept>
using namespace std;
void printArray(int *p, int length) {
for (int i = 0; i < length; i++) {
cout << p[i] << ", ";
}
}
int getdigit(int x, int d){
int a[] = {1, 10, 100};
return (x/a[d]) % 10;
}
void radixSort(int *p, int length, int d, int radix){
if(p == NULL || length <= 0 || d <= 0)
throw std::runtime_error("NULL Pointer");
int i;
int *c = new int[radix+1];
int *b = new int[length];
for(int j = 0; j != d; j++){
for(i = 0; i < radix + 1; i++)
c[i] = 0;
for(i = 0; i < length; i++){
int r = getdigit(p[i], j);
if(r > radix)
throw std::runtime_error("invaild input");
c[r] += 1;
}
for(i = 1; i < radix + 1; i++)
c[i] += c[i-1];
for(i = length - 1; i >= 0; i--){
int r = getdigit(p[i], j);
if(c[r] < 1)
throw std::runtime_error("error");
b[--c[r]] = p[i];
}
for(i = 0; i < length; i++)
p[i] = b[i];
}
delete [] c; c = NULL;
delete [] b; b = NULL;
}
int main()
{
int a[] = {30, 29, 50, 2, 42, 60};
radixSort(a, 6, 2, 9);
printArray(a, 6);
return 0;
}
複製程式碼執行結果為：
>> 2, 29, 30, 42, 50, 60,
複製程式碼2.7 歸併排序
#include <iostream>
#include <stdexcept>
using namespace std;
int INF = 0x7fffffff;
void printArray(int *p, int length) {
for (int i = 0; i < length; i++) {
cout << p[i] << ", ";
}
}
void mergeCore(int *p1, int *p2, int p1Len, int p2Len){
if(p1 == NULL || p2 == NULL || p1Len <= 0 || p2Len <= 0)
throw std::runtime_error("error");
int *l = new int[p1Len+1];
int *r = new int[p2Len+1];
int i;
int m = 0;
int n = 0;
for(i = 0; i < p1Len; i++)
l[i] = p1[i];
l[i] = INF;
for(i = 0; i < p2Len; i++)
r[i] = p2[i];
r[i] = INF;
i = 0;
while(i < p1Len + p2Len){
if(r[n] < l[m]){
p1[i++] = r[n++];
}else{
p1[i++] = l[m++];
}
}
delete [] l; l = NULL;
delete [] r; r = NULL;
}
void mergeSort(int *p, int length){
if(p == NULL || length <= 0)
throw std::runtime_error("error");
if(length == 1)
return;
int llen,rlen;
llen = length >> 1;
rlen = length - llen;
mergeSort(p,llen);
mergeSort(p+llen,rlen);
mergeCore(p,p+llen,llen,rlen);
}
int main()
{
int a[] = {30, 29, 50, 2, 42, 60};
mergeSort(a, 6);
printArray(a, 6);
return 0;
}
複製程式碼執行結果為：
>> 2, 29, 30, 42, 50, 60,
複製程式碼2.8 快速排序
#include <iostream>
#include <stdexcept>
using namespace std;
void printArray(int *p, int length) {
for (int i = 0; i < length; i++) {
cout << p[i] << ", ";
}
}
void quickSort(int *p, int length){
if(p == NULL || length <= 0)
throw std::runtime_error("error");
if(length == 1)
return;
int mid = 0;
int t;
for(int i = 0; i < length; i++){
if(p[i] < p[0]){
mid++;
t = p[mid]; p[mid] = p[i]; p[i] = t;
}
}
t = p[0]; p[0] = p[mid]; p[mid] = t;
int rlen = length - mid - 1;
if(mid > 0)
quickSort(p,mid);
if(rlen > 0)
quickSort(p+mid+1,rlen);
}
int main()
{
int a[] = {30, 29, 50, 2, 42, 60};
quickSort(a, 6);
printArray(a, 6);
return 0;
}
複製程式碼執行結果為：
>> 2, 29, 30, 42, 50, 60,
複製程式碼2.9 雙向掃描的快速排序
#include <iostream>
#include <stdexcept>
using namespace std;
void printArray(int *p, int length) {
for (int i = 0; i < length; i++) {
cout << p[i] << ", ";
}
}
void quickSortDouble(int *p, int length){
if(p == NULL || length <= 0)
throw std::runtime_error("error");
if(length == 1)
return;
int i = 0;
int t;
int mid = length;
while(true){
do { i++; } while( i < length && p[i] < p[0]);
do { mid--; } while( mid > 0 && p[mid] > p[0] );
if(i > mid) break;
t = p[i]; p[i] = p[mid]; p[mid] = t;
}
t = p[0]; p[0] = p[mid]; p[mid] = t;
int rlen = length - mid - 1;
if(mid > 0)
quickSortDouble(p,mid);
if(rlen > 0)
quickSortDouble(p+mid+1,rlen);
}
int main()
{
int a[] = {30, 29, 50, 2, 42, 60};
quickSortDouble(a, 6);
printArray(a, 6);
return 0;
}
複製程式碼執行結果為：
>> 2, 29, 30, 42, 50, 60,
複製程式碼2.10 堆排序
#include <iostream>
#include <stdexcept>
using namespace std;
void printArray(int *p, int length) {
for (int i = 0; i < length; i++) {
cout << p[i] << ", ";
}
}
void maxHeapify(int *p, int di, int length){
if(p == NULL || length <= 0 || di >= length || di < 0)
throw std::runtime_error("error");
int li = (di<<1)+1;
int t = p[di];
while(li < length){
if(li+1 < length && p[li+1] > p[li])
li++;
if(p[di] >= p[li])
break;
p[di] = p[li];
di = li;
li = (di<<1)+1;
}
p[di] = t;
}
void buildMaxHeap(int *p, int length){
if(p == NULL || length <= 0)
throw std::runtime_error("error");
for(int i=(length>>1)-1; i >= 0; i--){
maxHeapify(p,i,length);
}
}
void heapSort(int *p, int length){
if(p == NULL || length <= 0)
throw std::runtime_error("error");
int t;
for(int i=length; i > 0; i--){
buildMaxHeap(p,i);
t = p[i-1]; p[i-1] = p[0]; p[0] = t;
}
}
int main()
{
int a[] = {30, 29, 50, 2, 42, 60};
heapSort(a, 6);
printArray(a, 6);
return 0;
}
複製程式碼執行結果為：
>> 2, 29, 30, 42, 50, 60,
複製程式碼更多文章，歡迎訪問我的 Android 知識梳理系列：
- Android 知識梳理目錄：www.jianshu.com/p/fd82d1899…
- 個人主頁：lizejun.cn
- 個人知識總結目錄：lizejun.cn/categories/