C语言字符串首字母大写

#include <stdio.h>
#include <string.h>
main()
{
    char ch[100];
    int i=0,n=0;
    gets(ch);
    while(ch[i]!='\0')
    {
        if(i==0)
        {
            if(ch[i]>='a'&& ch[i]<='z') ch[i]-=32;
        }
        else if(ch[i]==' '&& ch[i+1]!=' ')
        {
            if(ch[i+1]>='a'&& ch[i+1]<='z') ch[i+1]-=32;
        }
        i++;
    }
    puts(ch);
    getchar();
 }