Calculating length of sub strings of consecutive characters MIPS - arrays

Question

I am writing a program using MIPs that takes an input string from the user and outputs the longest substring of consecutive identical characters. My problem seems to be that 'end' seems to be reached before the program outputs the target string. Any help is appreciated!
main:
la $a0,input_msg # Prompting input from user
li $v0,4
syscall
li $v0, 8 # Reading string and storing in memory
la $a0, input_string
li $a1, 100
syscall
li $t0, 0
la $t1, input_string # address of the first element
lb $a0, ($t1) # input_string[0] (the first character)
move $s0, $a0 # current_char=read_char();
move $s1, $a0 # previous_char = input_string[0];
move $s2, $a0 # final_char=input_string[0];
li $s3, 1 # current_num_chars=1;
li $s4, 1 # final_num_chars=1;
la $t5, new_line
loop:
addi $t0, $t0, 1 # for(k=1; k<i-1; k++) {
add $t1, $t1, $t0
lb $t3, ($t1)
beq $s5, $t3, print_final
move $s0, $t3 # current_char=input_string[k];
bne $s0, $s1, else # if(current_char == previous_char)
addi $s3, $s3, 1 # current_num_chars++;
bge $s3, $s4, increase_final # if(current_num_chars >= final_num_chars) {
move $s1, $s0
j loop # else do nothing
increase_final:
move $s2, $s0 # final_char=current_char;
move $s4, $s3 # final_num_chars=current_num_chars;
move $s1, $s0
j loop # }
else:
move $s1, $s0
j loop # else {
# current_num_chars=1;
# }
# }
print_final:
la $a0, output_msg
li $v0, 4
syscall
li $t2, 0
print_chars:
li $t2, 0 # for(k=0; k<final_num_chars; k++) {
beq $t2, $s3, end
move $a0, $s2 # print_char(final_char);
li $v0, 11
syscall
j print_chars # }
end:
li $v0, 4 # print_string("\n");
la $a0, new_line
syscall
li $v0, 10 # exit()
syscall

Answer 1

Your print_chars loop compares $t2 (which you just set to 0) to $s3 to decide whether or not to jump to end. Thus, it will always make the same comparison, and your loop will either exit the first time it is encountered, or never end.
Plus, the comment suggests that you should be comparing to $s4, not $s3.