strchr return value

#include<stdio.h>
#include<string.h>

int main(){
    int n,i,j;
    int cntp=0,cntt=0,cnta=0,flag=1;

    char *p1,*p2;
    char *p3;
    scanf("%d",&n);
    char s[100][100];
    for(i=0;i<n;++i)
    {
        scanf("%s",s[i]);
    }


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

        for(j=0;s[i][j]!='\0';j++)
        {
            if(s[i][j]=='P') cntp++;
            else if(s[i][j]=='A') cnta++;
            else if(s[i][j]=='T') cntt++;
            else  {flag=2;   break;}
        }
        if(flag==1&&cntp==1&&cntt==1&&cnta!=0)
        {
             p1=strchr(s[i],'P');
             p2=strchr(s[i],'T');
             p3=strrchr(s[i],'A');

              if((p1-s[i])*(p2-p1-1)==strlen(p2)-1)
                 flag=0;
        }
         if(flag==0)  puts("YES");
        else   puts("NO");
    }

    printf("%d\n",p1);
    printf("%d\n",p2);
    printf("%d\n",s[i]);
    printf("%d\n",p3);
    printf("%d\n",strlen(p2));

    return 0;
}

　A return input P and T values ​​of the string, not more than 1