Task · algorithms easy JavaScript ·

Summary ranges

/**
 * @param {number[]} nums
 * @returns {string[]}
 */
function summary_ranges(nums)

summary_ranges([0, 1, 2, 4, 5, 7])  // -> ["0->2", "4->5", "7"]
summary_ranges([0, 2, 3, 4, 6, 8, 9])  // -> ["0", "2->4", "6", "8->9"]
summary_ranges([])  // -> []

• #1DeepSeek V4 Pro 0423not solved · 9 of 10 testsanswer in 8.9 s · runtime 2.6 s · $0.0007

  ✓	summary_ranges([0, 1, 2, 4, 5, 7])expected ["0->2", "4->5", "7"]	2 ms
  ✓	summary_ranges([0, 2, 3, 4, 6, 8, 9])expected ["0", "2->4", "6", "8->9"]	<1 ms
  ✓	summary_ranges([])expected []	1 ms

  ✓ 1 ms✓ 1 ms✓ <1 ms✓ 1 ms✓ 1 ms⏱ time limit exceeded⏱ 95 ms
  Code

  /**
   * @param {number[]} nums
   * @returns {string[]}
   */
  function summary_ranges(nums) {
      const result = [];
      const n = nums.length;
      if (n === 0) return result;
      
      let start = nums[0];
      let prev = start;
      
      for (let i = 1; i < n; i++) {
          if (nums[i] === prev + 1) {
              prev = nums[i];
          } else {
              result.push(start === prev ? `${start}` : `${start}->${prev}`);
              start = nums[i];
              prev = start;
          }
      }
      result.push(start === prev ? `${start}` : `${start}->${prev}`);
      
      return result;
  }

  Second try

  not solved · 9 of 10 testsanswer in 5.6 s · $0.0009

  The model saw how many tests failed, the failing examples with the expected and returned values, and only why hidden tests failed, not their inputs. Doesn't count for places or the rating.

  ✓	summary_ranges([0, 1, 2, 4, 5, 7])expected ["0->2", "4->5", "7"]	2 ms
  ✓	summary_ranges([0, 2, 3, 4, 6, 8, 9])expected ["0", "2->4", "6", "8->9"]	<1 ms
  ✓	summary_ranges([])expected []	<1 ms

  ✓ <1 ms✓ 1 ms✓ <1 ms✓ <1 ms✓ <1 ms⏱ time limit exceeded⏱ 130 ms

  Code

  /**
   * @param {number[]} nums
   * @returns {string[]}
   */
  function summary_ranges(nums) {
      const result = [];
      const n = nums.length;
      if (n === 0) return result;
      
      let i = 0;
      while (i < n) {
          let start = nums[i];
          let j = i + 1;
          while (j < n && nums[j] === nums[j-1] + 1) {
              j++;
          }
          let end = nums[j-1];
          if (start === end) {
              result.push(start.toString());
          } else {
              result.push(start + "->" + end);
          }
          i = j;
      }
      return result;
  }

• #1OpenAI GPT-6.1 Terranot solved · 9 of 10 testsanswer in 2.2 s · runtime 2.6 s · $0.0009

  ✓	summary_ranges([0, 1, 2, 4, 5, 7])expected ["0->2", "4->5", "7"]	3 ms
  ✓	summary_ranges([0, 2, 3, 4, 6, 8, 9])expected ["0", "2->4", "6", "8->9"]	<1 ms
  ✓	summary_ranges([])expected []	<1 ms

  ✓ <1 ms✓ 1 ms✓ <1 ms✓ 6 ms✓ 1 ms⏱ time limit exceeded⏱ 105 ms
  Code

  function summary_ranges(nums) {
    const result = [];
    const n = nums.length;
    let i = 0;
  
    while (i < n) {
      const start = nums[i];
      let end = start;
      i++;
  
      while (i < n && nums[i] - end === 1) {
        end = nums[i++];
      }
  
      result.push(start === end ? String(start) : `${start}->${end}`);
    }
  
    return result;
  }

  Second try

  not solved · 9 of 10 testsanswer in 2.8 s · $0.0012

  The model saw how many tests failed, the failing examples with the expected and returned values, and only why hidden tests failed, not their inputs. Doesn't count for places or the rating.

  ✓	summary_ranges([0, 1, 2, 4, 5, 7])expected ["0->2", "4->5", "7"]	1 ms
  ✓	summary_ranges([0, 2, 3, 4, 6, 8, 9])expected ["0", "2->4", "6", "8->9"]	<1 ms
  ✓	summary_ranges([])expected []	<1 ms

  ✓ <1 ms✓ 1 ms✓ 1 ms✓ <1 ms✓ 1 ms⏱ time limit exceeded⏱ 127 ms

  Code

  function summary_ranges(nums) {
    const n = nums.length;
    if (n === 0) return [];
  
    const result = [];
    let start = nums[0];
    let prev = start;
  
    for (let i = 1; i < n; i++) {
      const value = nums[i];
      if (value - prev !== 1) {
        result.push(start === prev ? String(start) : start + "->" + prev);
        start = value;
      }
      prev = value;
    }
  
    result.push(start === prev ? String(start) : start + "->" + prev);
    return result;
  }

• #1Qwen3.8 Max (0902)not solved · 9 of 10 testsanswer in 7.6 s · runtime 2.6 s · $0.0026

  ✓	summary_ranges([0, 1, 2, 4, 5, 7])expected ["0->2", "4->5", "7"]	1 ms
  ✓	summary_ranges([0, 2, 3, 4, 6, 8, 9])expected ["0", "2->4", "6", "8->9"]	<1 ms
  ✓	summary_ranges([])expected []	1 ms

  ✓ 3 ms✓ 1 ms✓ 1 ms✓ 26 ms✓ 1 ms⏱ time limit exceeded⏱ 97 ms
  Code

  function summary_ranges(nums) {
    if (nums.length === 0) return [];
    
    const result = [];
    let start = nums[0];
    let prev = nums[0];
    
    for (let i = 1; i <= nums.length; i++) {
      if (i === nums.length || nums[i] !== prev + 1) {
        if (start === prev) {
          result.push(String(start));
        } else {
          result.push(start + "->" + prev);
        }
        if (i < nums.length) {
          start = nums[i];
          prev = nums[i];
        }
      } else {
        prev = nums[i];
      }
    }
    
    return result;
  }

  Second try

  not solved · 9 of 10 testsanswer in 9.5 s · $0.0039

  The model saw how many tests failed, the failing examples with the expected and returned values, and only why hidden tests failed, not their inputs. Doesn't count for places or the rating.

  ✓	summary_ranges([0, 1, 2, 4, 5, 7])expected ["0->2", "4->5", "7"]	3 ms
  ✓	summary_ranges([0, 2, 3, 4, 6, 8, 9])expected ["0", "2->4", "6", "8->9"]	1 ms
  ✓	summary_ranges([])expected []	<1 ms

  ✓ <1 ms✓ <1 ms✓ <1 ms✓ 4 ms✓ 1 ms⏱ time limit exceeded⏱ 118 ms

  Code

  function summary_ranges(nums) {
    const n = nums.length;
    if (n === 0) return [];
    
    const result = [];
    let i = 0;
    
    while (i < n) {
      let j = i;
      while (j + 1 < n && nums[j + 1] === nums[j] + 1) {
        j++;
      }
      if (i === j) {
        result.push(String(nums[i]));
      } else {
        result.push(nums[i] + "->" + nums[j]);
      }
      i = j + 1;
    }
    
    return result;
  }

• #1Mistral Devstral 2 2512not solved · 9 of 10 testsanswer in 1.2 s · runtime 2.7 s · $0.0005

  ✓	summary_ranges([0, 1, 2, 4, 5, 7])expected ["0->2", "4->5", "7"]	2 ms
  ✓	summary_ranges([0, 2, 3, 4, 6, 8, 9])expected ["0", "2->4", "6", "8->9"]	2 ms
  ✓	summary_ranges([])expected []	<1 ms

  ✓ <1 ms✓ 1 ms✓ 35 ms✓ <1 ms✓ <1 ms⏱ time limit exceeded⏱ 134 ms
  Code

  function summary_ranges(nums) {
      if (nums.length === 0) return [];
      const ranges = [];
      let start = nums[0];
      for (let i = 1; i < nums.length; i++) {
          if (nums[i] !== nums[i - 1] + 1) {
              if (start === nums[i - 1]) {
                  ranges.push(start.toString());
              } else {
                  ranges.push(start + '->' + nums[i - 1]);
              }
              start = nums[i];
          }
      }
      if (start === nums[nums.length - 1]) {
          ranges.push(start.toString());
      } else {
          ranges.push(start + '->' + nums[nums.length - 1]);
      }
      return ranges;
  }

  Second try

  not solved · 9 of 10 testsanswer in 1.1 s · $0.0005

  The model saw how many tests failed, the failing examples with the expected and returned values, and only why hidden tests failed, not their inputs. Doesn't count for places or the rating.

  ✓	summary_ranges([0, 1, 2, 4, 5, 7])expected ["0->2", "4->5", "7"]	2 ms
  ✓	summary_ranges([0, 2, 3, 4, 6, 8, 9])expected ["0", "2->4", "6", "8->9"]	<1 ms
  ✓	summary_ranges([])expected []	<1 ms

  ✓ 5 ms✓ 31 ms✓ 1 ms✓ 2 ms✓ 4 ms⏱ time limit exceeded⏱ 134 ms

  Code

  function summary_ranges(nums) {
      const ranges = [];
      let start = nums[0];
      for (let i = 1; i <= nums.length; i++) {
          if (i === nums.length || nums[i] !== nums[i - 1] + 1) {
              ranges.push(start === nums[i - 1] ? start.toString() : start + '->' + nums[i - 1]);
              if (i < nums.length) start = nums[i];
          }
      }
      return ranges;
  }

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