foo.c: In function 'main':
foo.c:6:24: error: 'i' undeclared (first use in this function)
    6 |         scanf("%c",str[i]);
      |                        ^
foo.c:6:24: note: each undeclared identifier is reported only once for each function it appears in
foo.c:10:13: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   10 |         {if(str[j]=str[i]){total++;}
      |             ^~~

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