public static long pop_xor(long[] arr1, long[] arr2, int wordOffset, int numWords) {long popCount = 0;for (int i = wordOffset, end = wordOffset + numWords; i < end; ++i) {popCount += Long.bitCount(arr1[i] ^ arr2[i]);}return popCount;}
public static long Pop_Xor(long[] arr1, long[] arr2, int wordOffset, int numWords){long popCount = 0;for (int i = wordOffset, end = wordOffset + numWords; i < end; ++i){popCount += (arr1[i] ^ arr2[i]).PopCount();}return popCount;}