0567-permutation-in-string.rs

implSolution{
pubfncheck_inclusion(s1:String,s2:String) -> bool{
if s1.len() > s2.len(){
returnfalse;
}

let(mut s1_cnt,mut s2_cnt) = ([0;26],[0;26]);
for i in0..s1.len(){
 s1_cnt[s1.chars().nth(i).unwrap()asusize - 'a'asusize] += 1;
 s2_cnt[s2.chars().nth(i).unwrap()asusize - 'a'asusize] += 1;
}

letmut matches = 0;
for i in0..26{
 matches = if s1_cnt[i] == s2_cnt[i]{ matches + 1}else{ matches };
}

letmut l = 0;
for r in s1.len()..s2.len(){
if matches == 26{
returntrue;
}

letmut index = s2.chars().nth(r).unwrap()asusize - 'a'asusize;
 s2_cnt[index] += 1;
if s1_cnt[index] == s2_cnt[index]{
 matches += 1;
}elseif s1_cnt[index] + 1 == s2_cnt[index]{
 matches -= 1;
}

 index = s2.chars().nth(l).unwrap()asusize - 'a'asusize;
 s2_cnt[index] -= 1;
if s1_cnt[index] == s2_cnt[index]{
 matches += 1;
}elseif s1_cnt[index] - 1 == s2_cnt[index]{
 matches -= 1;
}

 l += 1;
}

 matches == 26
}
}