Login Security

//gcc 5.4.0

#include  <stdio.h>

int main()
{
    short int caracteres, i, j, cont, cont1=0, cont2=0, cont3=0, cont4=0;
    char vector[30+1];
    char validos[11+1] = {'#','$','%','&','*',',','.',';','?','@','~',':'};

    do{
        scanf("%hd",&caracteres);
        //printf("%d\n",caracteres);
    }while((caracteres < 1)||(caracteres > 30));

    scanf("%s",vector);
    //printf("%s",vector);

    if(caracteres >= 8){
        for(i = 0; i < caracteres; i++){

            if(vector[i] >= 'a' && vector[i] <= 'z'){
                cont4++;
            }
            else{
                if(vector[i] >= 'A' && vector[i] <= 'Z'){
                cont3++;
                }
                else{
                     if(vector[i] >= '0' && vector[i] <= '9'){
                     cont2++;
                     }
                     else{
                         for(j = 0; j <= 11; j++){
                             if(vector[i] == validos[j]){
                                 cont1++;
                             }
                         }
                     }
                    }
                 }
        }
        }

    cont = cont1+cont2+cont3+cont4;

    if((cont1 > 0)&&(cont2 > 0)&&(cont3 > 0)&&(cont4 > 0)&&(cont == caracteres)){
        printf("SI");
    }
    else{
        printf("NO");
    }

    return 0;
}