P10.WAP to convert a given string into sentences case

#include <stdio.h>
int main()
{
    char str[200];
    int i;


    printf("Enter a string: ");
    gets(str);

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

        if(i==0)
        {
            if((str[i]>='a' && str[i]<='z'))
                str[i]=str[i]-32;
            continue;
        }
        if(str[i]==' ')
        {

            ++i;

            if(str[i]>='a' && str[i]<='z')
            {
                str[i]=str[i]-32;
                continue;
            }
        }
        else
        {

            if(str[i]>='A' && str[i]<='Z')
                str[i]=str[i]+32;
        }
    }

    printf("Capitalize string is: %s\n",str);

    return 0;
}