#include <stdio.h>

#include <conio.h>

#include <string.h>

int soluongchuso(char *str)

{

int demchuso=0;

// Ham strlen -- xac dinh do dai cua chuoi ki tu ( can include string.h )

for(int i=0;i<strlen(str);i++)

{

if(str[i]>='0' && str[i]<='9')

{

//Neu ki tu thu i la chu so thi tang bien dem chu so len 1

demchuso++;

}

}

return demchuso;

}

void nhapchuoi(char *str)

{

int i=0;

do

{

str[i]=getche();

// Neu ki tu nhap vao la phim Enter thi dung nhap du lieu

if(str[i]=='\r')

break;

i++;

// Cho phep nhap ki tu tiep theo khi so luong ki tu da nhap chua >50

}while(i<50);

}

void main()

{

char chuoi[51];

printf("Nhap chuoi (khong qua 50 ki tu): ");

nhapchuoi(chuoi);

printf("So luong chu so trong chuoi: %d",soluongchuso(chuoi));

}