前缀异或he前缀和(区域检索)

Posted 2021-06-06 秦枫-_-

class Solution {
    public int[] xorQueries(int[] arr, int[][] queries) {
    int []asc=new int[arr.length+1];
    for(int i=0;i<arr.length;i++){
          asc[i+1]=asc[i]^arr[i];
      }
    int []res=new int[queries.length];
    for(int i=0;i<queries.length;i++){
        int m1=queries[i][0],m2=queries[i][1];
        res[i]=asc[m1]^asc[m2+1];
    }
    return res;
    }
}

类似的还有前缀和

class NumArray {
     int []preall;
    public NumArray(int[] nums) {
        preall=new int[nums.length+1];
        preall[0]=0;
     for(int i=0;i<nums.length;i++){
         preall[i+1]=preall[i]+nums[i];
     }
    }
    
    public int sumRange(int left, int right) {
      return preall[right+1]-preall[left];
    }
}