[Bài tập]:Day 5:Array character

Bài 1:1. Write a program which prints the letters in a char array in reverse order. For

example, if the array contains {'c', 's', 'c', '2', '6', '1'}the output (to the terminal)

should be "162csc"

Code:char a[10];

int i;

for(i=0;i<9;i++){

            printf("Xin moi nhap ki tu thu %d: ",i);

            scanf("%s",&a[i]);

}

for(i=8;i>=0;i=i-1){

            printf("%c",a[i]);

}\

Bài 2: Write a  program : declare a char array and the size of the array (of type char). This function counts the number of digit letters in the char array.

Code:char a[10];

int i,s=0;

for(i=0;i<10;i++){

            printf("Xin moi nhap ki tu %d: ",i+1);

            scanf("%s",&a[i]);

            }

for(i=0;i<10;i++){

 if(a[i]>47 && a[i]<58){

   s=s+1;

   }

  }        

printf("Trong mang co %d phan tu la so",s);  

 Bài 3: Write a program that counts the number of words in a string

code:char a[100];

int i,s=0;

printf("Nhap Chuoi: ");

gets(&a);

for(i=0;i<100;i++){

            if(a[i]==' '){

              s=s+1;          

            }

}

Bài 4:Write a program that accept two string, after checking if string1 equals string2 then print 'string 1 equals string2', else print string1 less than or greater than string 2.

Code:char a[100],b[100]; int i,s=0,t=0; printf("Nhap Chuoi: "); gets(&a); for(i=0;a[i]!='\0';i++){ if(a[i]==' '){ s=s+1; } } printf("Nhap Chuoi: "); gets(&b); for(i=0;b[i]!='\0';i++){ if(b[i]==' '){ t=t+1; } } if(t>s){ printf("Array 2 greater than array 1"); } else if(s==t){ printf("2 array is equal"); } else{ printf("Array 1 greater than array 2"); }

 

Bài 5:Write a function that scans a character array for the character - and replaces it with _

Code:char a[100];

int i;

printf("Nhap Chuoi: ");

gets(&a);

for(i=0;a[i]!='\0';i++){

            if(a[i]=='-'){

              a[i]='_';          

            }

}

            printf("Day sau khi doi: %s",a);