C + + implementation bit array

When we encounter a lot of integer sorting to save memory space we can consider using a bit array to implement, the disadvantage is that it only applies to positive integers.

Thought:

In a 32-bit system with an int type of 4 bytes, a bitwise to calculate an int type can record 32 numbers, therefore, an int array and a shift are used to implement the related function.

C + + implementation bit array

#include <iostream>using namespace std;const unsigned int bitvalue[32]={0x80000000,0x40000000,0x20000000, 0x10000000,0x08000000,0x04000000,0x02000000,0x01000000,0x00800000,0x00400000,0x00200000,0x00100000,0x00080000, 0X00040000,0X00020000,0X00010000,0X00008000,0X00004000,0X00002000,0X00001000,0X00000800,0X00000400,0X00000200, 0x00000100,0x00000080,0x00000040,0x00000020,0x00000010,0x00000008,0x00000004,0x00000002,0x00000001};const int Bitlen =sizeof (int) *8;class bitarray{private:unsigned int len;unsigned int *bit;public:bitarray (unsigned int length) { if (length<0) {throw "length less than 0";} this->len=length;bit= New unsigned int[length/bitlen+ (length%bitlen>0?1:0)] ();//initialized to 0}unsigned int getbit (int Index) {if (index<0| | Index>len) {Throw "index out of Bounds";} unsigned int data=bit[index/bitlen];return (Data&bitvalue[index%bitlen]) >> (bitlen-index%bitlen-1);} void setbit (unsigned int index,unsigned int value) {if (index<0| | Index>len) {Throw "index out of Bounds";} if (value!=1&&value!=0{Throw ' value can only be 1 or 0 ";} unsigned int data=bit[index/bitlen];//calculates which int value in the array if (value==1) {Bit[index/bitlen]=data|bitvalue[index%bitlen];} Else{bit[index/bitlen]=data&~bitvalue[index%bitlen];}} unsigned int getlength () {return this->len;} ~bitarray () {delete[] bit;}; int main () {Try{bitarray barray (1000000); Barray.setbit (99999,1); Barray.setbit (201,1); cout<<barray.getbit (0) <<endl;cout<<barray.getbit (99999) <<endl;cout<<barray.getbit (10000) <<endl;} catch (char *str_ex) {Cout<<str_ex<<endl;} Cin.get (); return 0;}

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C + + implementation bit array