let items = "000001111111122223456448766666".split('').map(x => parseInt(x)).sort();

// let items = "qwertwuxypoiuz".split('').sort();

//let items = "012346789".split('').map(x=> parseInt(x));

function binary_search(itemType, key, low, high) {

let middle = Math.floor((low + high) / 2);

if (low > high) {

return -1;

}

if (itemType[middle] == key) {

return middle;

}

if (itemType[middle] > key) {

return binary_search(itemType, key, low, middle - 1);

} else {

return binary_search(itemType, key, middle + 1, high);

}

}

function binary_search_high(itemType, key, low, high) {

let middle = Math.floor((low + high) / 2);

if (low > high) {

return high;

}

if (itemType[middle] > key) {

return binary_search_high(itemType, key, low, middle - 1);

} else {

return binary_search_high(itemType, key, middle + 1, high);

}

}

function binary_search_low(itemType, key, low, high) {

let middle = Math.floor((low + high) / 2);

if (low > high) {

return low;

}

if (itemType[middle] < key) {

return binary_search_low(itemType, key, middle + 1, high);

} else {

return binary_search_low(itemType, key, low, middle - 1);

}

}

console.log(items.map((s, idx) => `${idx}-${s}`));

const key = 'u'

console.log(`search item : ${key}`);

//let idx = binary_search(items, key, 0, items.length);

//console.log(`search index: ${idx}`);

let low = binary_search_low(items, key, 0, items.length);

let high = binary_search_high(items, key, 0, items.length);

console.log(`range: ${low} -- ${high}`);