Issue with retrieving the positions of two numbers in an array

Question

Issue with retrieving the positions of two numbers in an array

I encountered a challenge:

I have an array of integers nums and an integer target. My goal is to find the indices of two numbers in the array that add up to the specified target.

Example 1:

Input: nums = [2,7,11,15], target = 9
Output: [0,1]
Output: This is because nums[0] + nums[1] equals 9, so we return [0, 1].

After experimenting with some code utilizing set and Map, I was able to get the sum of values in the array.

However, my current challenge lies in returning the indices.

const arr = [{key1: 2}, {key1: 7}, {key1: 11}, {key1: 15}];
const k = 9;
const valueSet = new Set(arr.flatMap((x) => Object.values(x)));
const valueArray = [...valueSet];

valueArray.forEach((v1, i1) => {
    for (let i2 = i1 + 1; i2 < valueArray.length; i2++) {
        if ((v1 + valueArray[i2]) === k) {
            // Return the indices
            return valueArray[i2];
        }
    }
});

javascript typescript ecmascript-6

Answer 1

Answer №1

To find the precise combination of indexes that will yield the desired sum, you must diligently parse through the data.

Feel free to refer to the code snippet below for assistance:

const arr = [{ key1: 2 }, { key1: 7 }, { key1: 11 }, { key1: 15 }];
const k = 9;
let valueSet = new Set(arr.flatMap((x) => Object.values(x)));
let valueArray = [...valueSet];

let indices;
let isFound = false;
// valueArray.forEach((v1, i1) => {
for (let i1 = 0; i1 < valueArray.length && !isFound; i1++) {
  for (let i2 = i1 + 1; i2 < valueArray.length && !isFound; i2++) {
    if ((valueArray[i1] + valueArray[i2]) === k) {
      //Determine and display the Indices
      indices = [i1, i2];
      isFound = true;;
    }
  }
}
console.log(indices);

Answer 2

To find the precise combination of indexes that will yield the desired sum, you must diligently parse through the data.

Feel free to refer to the code snippet below for assistance:

const arr = [{ key1: 2 }, { key1: 7 }, { key1: 11 }, { key1: 15 }];
const k = 9;
let valueSet = new Set(arr.flatMap((x) => Object.values(x)));
let valueArray = [...valueSet];

let indices;
let isFound = false;
// valueArray.forEach((v1, i1) => {
for (let i1 = 0; i1 < valueArray.length && !isFound; i1++) {
  for (let i2 = i1 + 1; i2 < valueArray.length && !isFound; i2++) {
    if ((valueArray[i1] + valueArray[i2]) === k) {
      //Determine and display the Indices
      indices = [i1, i2];
      isFound = true;;
    }
  }
}
console.log(indices);

Answer 3

Answer №2

The solution provided by Nitheesh is effective. To understand why your initial approach did not work, here's an explanation:

When using forEach to iterate over an array, the callback function is invoked for each element in the array. Using return within a forEach loop only exits the current element's callback, not the entire iteration. Therefore, a return in a forEach loop is akin to a continue in a traditional for loop.

For more information, you can refer to this source.

Answer 4

The solution provided by Nitheesh is effective. To understand why your initial approach did not work, here's an explanation:

When using forEach to iterate over an array, the callback function is invoked for each element in the array. Using return within a forEach loop only exits the current element's callback, not the entire iteration. Therefore, a return in a forEach loop is akin to a continue in a traditional for loop.

For more information, you can refer to this source.

Answer 5

Answer №3

To start, extract the values from the array using the keys

 [{key1: 2},{key1: 7},{key1: 11},{key1: 15}];

. Next, iterate through the values array and check if the sum of two elements equals the target value. For example, (7 + 2 == 9).

const arr = [{key1: 2},{key1: 7},{key1: 11},{key1: 15}];
const k = 9;
nums = arr.map((o) => {
  return Object.values(o)[0]
})

const twoSum = (nums, target) => {
    for(let i = 0; i < nums.length; i++){
        for(let j = i+1; j < nums.length; j++){
            if(nums[i] + nums[j] == target){
                return [i, j]
            }
        }
    }
};

console.log(twoSum(nums, k))

Answer 6

To start, extract the values from the array using the keys

 [{key1: 2},{key1: 7},{key1: 11},{key1: 15}];

. Next, iterate through the values array and check if the sum of two elements equals the target value. For example, (7 + 2 == 9).

const arr = [{key1: 2},{key1: 7},{key1: 11},{key1: 15}];
const k = 9;
nums = arr.map((o) => {
  return Object.values(o)[0]
})

const twoSum = (nums, target) => {
    for(let i = 0; i < nums.length; i++){
        for(let j = i+1; j < nums.length; j++){
            if(nums[i] + nums[j] == target){
                return [i, j]
            }
        }
    }
};

console.log(twoSum(nums, k))

Answer 7

Answer №4

Here is a possible solution:

function findIndices(target, array) {
  let output = [];

  for (let i = 0; i < array.length; i++) {
    for (let j = 0; j < array.length; j++) {
      if (array[i] + array[j] === target) {
        return (output = [array[i], array[j]]);
      }
    }
  }

  return output;
}

function searchIndices(target, array) {
  let output = [];

  for (const num1 of array) {
    for (const num2 of array) {
      if (num1 + num2 === target) {
        return (output = [num1, num2]);
      }
    }
  }

  return output;
}

function locateIndices(target, array) {
  return array.reduce((accumulator, current, index, arr) => {
    let output = [...accumulator, current];

    for (const num of accumulator) {
      if (num + current === target) {
        output = [num, current];
        arr.splice(1);
        break;
      }
    }

    return output;
  }, []);
}

Answer 8

Here is a possible solution:

function findIndices(target, array) {
  let output = [];

  for (let i = 0; i < array.length; i++) {
    for (let j = 0; j < array.length; j++) {
      if (array[i] + array[j] === target) {
        return (output = [array[i], array[j]]);
      }
    }
  }

  return output;
}

function searchIndices(target, array) {
  let output = [];

  for (const num1 of array) {
    for (const num2 of array) {
      if (num1 + num2 === target) {
        return (output = [num1, num2]);
      }
    }
  }

  return output;
}

function locateIndices(target, array) {
  return array.reduce((accumulator, current, index, arr) => {
    let output = [...accumulator, current];

    for (const num of accumulator) {
      if (num + current === target) {
        output = [num, current];
        arr.splice(1);
        break;
      }
    }

    return output;
  }, []);
}

Answer 9

Answer №5

const items = [{ name: "apple" }, { name: "banana" }, { name: "orange" }, { name: "grape" }];
const target = "cherry";
let itemSet = new Set(items.flatMap((item) => Object.values(item)));
let itemArray = [...itemSet];

itemArray.forEach((value, index) => {
    let index2 = itemArray.findIndex((v) => v === target - value);
    index2 > -1 && console.log([index, index2]);
})

Answer 10

const items = [{ name: "apple" }, { name: "banana" }, { name: "orange" }, { name: "grape" }];
const target = "cherry";
let itemSet = new Set(items.flatMap((item) => Object.values(item)));
let itemArray = [...itemSet];

itemArray.forEach((value, index) => {
    let index2 = itemArray.findIndex((v) => v === target - value);
    index2 > -1 && console.log([index, index2]);
})

Issue with retrieving the positions of two numbers in an array

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

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