Calculate the number of 1

_ Int64 countone (_ int64 N) {_ int64 COUNT = 0; If (n = 0) Count = 0; else if (n> 1 & n <10) Count = 1; else {_ int64 highest = N; _ int64 bit = 0; while (highest> = 10) {highest = highest/10; bit ++;} _ int64 Weight = (_ int64) Pow (10, bit); If (highest = 1) {COUNT = countone (weight-1) + countone (n-weight) + N-weight + 1;} else {COUNT = highest * countone (weight-1) + countone (n-highest * weigh T) + weight ;}} return count ;}< pre name = "code" class = "CPP"> publiclong countone2 (long n) {Long Count = 0; long I = 1; long current = 0, after = 0, before = 0; while (n/I )! = 0) {current = (N/I) % 10; before = N/(I * 10); after = N-(N/I) * I; if (current> 1) Count = count + (before + 1) * I; elseif (current = 0) Count = count + before * I; elseif (current = 1) count = count + before * I + after + 1; I = I * 10;} return count ;}

Calculate the number of 1