Sword refers to only one occurrence of a number in an offer array

The title describes an array of integers in addition to the two numbers, the other numbers appear two times. Please write the program to find the two only occurrences of the number. Idea: Because there are 2 numbers that only appear once, and the other numbers are 2 times, you can get the difference or the result value of the last 2 occurrences of the number by XOR operation. This value must not be 0. Then find out this number binary, the lowest bit is 1 of the number of bits, it is necessary that one is 0, one is 1. By this condition, the original array is divided into 2 parts, respectively, and the result is obtained. Code:

1 classSolution {2  Public:3     voidFindnumsappearonce (vector<int> Data,int* NUM1,int*num2)4     {5         intres =0, tag =0;6         if(Data.empty ())7         {8NUM1 = Num2 =0;9         }Ten  One          for(inti =0; I < data.size (); i++) A         { -Res ^=Data[i];  -         } the  -          for(; tag < +; tag++) -         { -             if(Res & (1<<tag))! =0) +                  Break; -         } +  A          for(inti =0; I < data.size (); i++) at         { -             if((data[i) & (1<< tag) = =0) -*num1 ^=Data[i]; -             Else -*num2 ^=Data[i]; -         } in     } -};

Question 2:

There is one number in an array that appears only once.

Ideas:

Directly traversing an XOR or an entire array, you get the number that appears only once.

Question 3:

In an array, a number appears 1 times, and the others appear 3 times

Ideas:

Open up an array of digits, traverse the far array to record 2 of all elements, and the number of bits.

Iterate through the array of bits, divide the value by 3, and the last array of digits left is the last one that appears only once.

Code:

1  Public Static intFIND1FROM3 (int[] a) {2         int[] bits =New int[32];3         intLen =a.length;4          for(inti = 0; i < Len; i++){5              for(intj = 0; J < 32; J + +){6BITS[J] = Bits[j] + ((a[i]>>>j) & 1);7             }8         }9         intres = 0;Ten          for(inti = 0; I < 32; i++){ One             if(Bits[i]% 3!=0){ Ares = Res | (1 << i);

Sword refers to only one occurrence of a number in an offer array