const NUMS = [1, 2, 3, 4, 5, 6, 7, 8, 9];
const SUM = 100;
function printVariation(allOperators) {
const joinedNums = [];
const operators = [];
// joining numgers
allOperators.forEach((o, index) => {
if (o === 'join') {
if (index) {
const prevNum = joinedNums[joinedNums.length - 1];
joinedNums[joinedNums.length - 1] = prevNum * 10 + NUMS[index + 1];
} else {
const prevNum = NUMS[index];
joinedNums.push(prevNum * 10 + NUMS[index + 1]);
}
} else {
if (index === 0) {
joinedNums.push(NUMS[0]);
}
joinedNums.push(NUMS[index + 1]);
operators.push(o);
}
});
let result = joinedNums[0];
const sequence = [joinedNums[0]];
// calculating the result
operators.forEach((o, index) => {
if (o == '+') {
result += joinedNums[index + 1];
} else {
result -= joinedNums[index + 1];
}
sequence.push(o);
sequence.push(joinedNums[index + 1]);
});
if (result === SUM) {
console.log(sequence.join(' '));
}
}
function findVariations(operators = []) {
if (operators.length >= 8) {
printVariation(operators);
return;
}
const v1 = operators.slice();
v1.push('+')
findVariations(v1);
const v2 = operators.slice();
v2.push('-')
findVariations(v2);
const v3 = operators.slice();
v3.push('join')
findVariations(v3);
}
findVariations();
