前导0和二进制1个数

    int length(int num) {int ret = 0;if (num >> 16 == 0) {ret += 16;num <<= 16;}if (num >> 24 == 0) {ret += 8;num <<= 8;}if (num >> 28 == 0) {ret += 4;num <<= 4;}if (num >> 30 == 0) {ret += 2;num <<= 2;}if (num >> 31 == 0) {ret += 1;}return ret;}int count(int num) {num = (num & 0x55555555) + ((num >> 1) & 0x55555555);num = (num & 0x33333333) + ((num >> 2) & 0x33333333);num = (num & 0x0f0f0f0f) + ((num >> 4) & 0x0f0f0f0f);num = (num & 0x00ff00ff) + ((num >> 8) & 0x00ff00ff);num = (num & 0x0000ffff) + ((num >> 16) & 0x0000ffff);return num;}