関連ワード:  how to find size of number in c++    how to find length of number in c++    how to get length of number in c++    how to find size of vector in c++    how to find size of array in c++    how to find size of string in c++    how to find size of map in c++    how to find size of set in c++    how to find size of matrix in c++    how to find size of integer in c++