The question
Find the first non-repeated (unique) character in a given string.
My answer
At first glance I am tempted to start from the left and add each character go to a hashtable with the number of times I have seen it. Once I have gone through the whole string I will do it again now searching for the first character that returns 1.
This seems to be the right solution so lets look at the code:
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function checkFirstNonRepeated(word) {
var map = {};
for (var i = 0; i < word.length; i++) {
if (undefined === map[word[i]]) {
map[word[i]] = 1;
} else {
map[word[i]]++;
}
}
for (i = 0; i < word.length; i++) {
if (1 === map[word[i]]) {
return word[i];
}
}
}
function test() {
if (checkFirstNonRepeated('asdfasdf') === undefined) {
console.log('success');
}
if (checkFirstNonRepeated('asdfasd') === 'f') {
console.log('success');
}
}
test(); // Prints success twice
computer_science algorithms javascript programming