【当前排名42710】挑战leetcode进入前1w名

李恒道

https://leetcode.cn/problems/double-modular-exponentiation/submissions/595784284/
这题真的涨知识了
太卡边界了

var getGoodIndices = function (variables, target) {
  let ans = [];
  for (let index = 0; index < variables.length; index++) {
    const [a, b, c, d] = variables[index];
    if (pow(pow(a, b, 10), c, d) == target) {
      ans.push(index);
    }
  }
  return ans;
};

const pow = (a, b, mod) => {
  let mul = a;
  let ans = 1;
  while (b !== 0) {
    if ((b & 1 )!== 0) {
      ans = ans*mul% mod;
    }
    b = b >> 1;
    mul = mul * mul% mod;
  }
  return ans;
};

李恒道

https://leetcode.cn/submissions/detail/595784111/
全排列

var permuteUnique = function (nums) {
  const swap = (a, b) => {
    const temp = nums[b];
    nums[b] = nums[a];
    nums[a] = temp;
  };
  const ans = [];
  const cache = new Map();
  const dfs = (i) => {
    if (i == nums.length - 1) {
      const tag = nums.join(" ");
      if (cache.has(tag) ) {
        return;
      }
      cache.set(tag, true);
      ans.push([...nums]);
      return;
    }
    for (let index = i; index < nums.length; index++) {
      swap(i, index);
      dfs(i + 1);
      swap(i, index);
    }
  };
  dfs(0);
  return ans;
};

李恒道

https://leetcode.cn/problems/people-whose-list-of-favorite-companies-is-not-a-subset-of-another-list/submissions/595809496/
模拟题
map硬爆了

var peopleIndexes = function (favoriteCompanies) {
  const strToMap = new Map();
  const list = [];
  for (let index = 0; index < favoriteCompanies.length; index++) {
    const favoriteCompanie = favoriteCompanies[index];
    const set = new Set();
    for (let index = 0; index < favoriteCompanie.length; index++) {
      const str = favoriteCompanie[index];
      strToMap.set(str, strToMap.get(str) ?? []);
      strToMap.get(str).push(set);
      set.add(str);
    }
    list.push(set);
  }
  const cache = new Map();
  const isChild = (setA, setB) => {
    if (cache.has(setA)) {
      if (cache.get(setA).has(setB)) {
        return cache.get(setA).get(setB);
      }
    }
    if (setA == setB) {
      return false;
    }
    let ans = true;
    for (const str of setB.values()) {
      if (setA.has(str) == false) {
        ans = false;
        break;
      }
    }
    if (cache.has(setA) == false) {
      cache.set(setA, new Map());
    }
    if (cache.get(setA).has(setB) == false) {
      cache.get(setA).set(setB, ans);
    }
    return ans;
  };
  let ans = [];
  for (let index = 0; index < list.length; index++) {
    const item = list[index];
    let noChild = true;
    for (const str of item.values()) {
      for (const setA of strToMap.get(str)) {
        if (isChild(setA, item)) {
          noChild = false;
        }
        if (!noChild) {
          break;
        }
      }
      if (!noChild) {
        break;
      }
    }
    if (noChild) {
      ans.push(index);
    }
  }
  return ans;
};

李恒道

https://leetcode.cn/problems/average-salary-excluding-the-minimum-and-maximum-salary/submissions/595810894/?envType=study-plan-v2&envId=programming-skills
平均提，秒了

func average(salary []int) float64 {
 var maxValue,minValue float64= float64(salary[0]), float64(salary[0])
 var total float64
    for i := 0; i < len(salary); i++ {
        total+=float64(salary[i]);
        maxValue= math.Max(maxValue, float64(salary[i]))
        minValue= math.Min(minValue, float64(salary[i]))
    }
    return (total - maxValue - minValue) / float64(len(salary) - 2)
}

李恒道

https://leetcode.cn/problems/maximum-69-number/submissions/595811321/
秒了

func maximum69Number (num int) int {
str:=[]rune(strconv.Itoa(num))
    for i := 0; i < len(str); i++ {
        if str[i]=='6' {
            str[i]='9'
            break;
        }
    }
    ret,_:=strconv.Atoi(string(str))
    return  ret
}

李恒道

https://leetcode.cn/problems/rotating-the-box/submissions/595815430/
秒了

var rotateTheBox = function (boxGrid) {
  const rotatedMatrix = rotateMatrix(boxGrid);
  for (let index = rotatedMatrix.length - 1; index >= 0; index--) {
    for (let indey = 0; indey < rotatedMatrix[0].length; indey++) {
      let x = index;
      const char = rotatedMatrix[x][indey];
      if (char == "#") {
        rotatedMatrix[index][indey] = ".";
        while (x + 1 < rotatedMatrix.length&& rotatedMatrix[x + 1][indey] == ".") {
          x = x + 1;
        }
        rotatedMatrix[x][indey] = char;
      }
    }
  }
  return rotatedMatrix
};
function rotateMatrix(matrix) {
  const rows = matrix.length;
  const cols = matrix[0].length;
  const result = Array.from({ length: cols }, () => Array(rows).fill(0));

  for (let i = 0; i < rows; i++) {
    for (let j = 0; j < cols; j++) {
      result[j][rows - 1 - i] = matrix[i][j];
    }
  }

  return result;
}

李恒道

https://leetcode.cn/problems/intersection-of-two-arrays-ii/submissions/595881524/
穿了

var intersect = function (nums1, nums2) {
  const map1 = new Map();
  for (const num of nums1) {
    map1.set(num, (map1.get(num) ?? 0) + 1);
  }
  let ans=[]
  for (const num of nums2) {
    if (map1.has(num)) {
      let times = map1.get(num);
      ans.push(num)
      times--
      if(times==0){
        map1.delete(num)
      }else{
        map1.set(num,times)
      }
    }

  }
  return ans
};

李恒道

https://leetcode.cn/problems/intersection-of-two-arrays/submissions/595881599/
穿

var intersection  = function (nums1, nums2) {
  const map1 = new Map();
  for (const num of nums1) {
    map1.set(num, (map1.get(num) ?? 0) + 1);
  }
  let ans=[]
  for (const num of nums2) {
    if (map1.has(num)) {
      let times = map1.get(num);
      ans.push(num)
      times--
      map1.delete(num)
    }

  }
  return ans
};

李恒道

https://leetcode.cn/problems/students-and-examinations/?envType=study-plan-v2&envId=sql-free-50
大过年做个sql水一下

SELECT Students.*, Subjects.*, COUNT(Examinations.subject_name) AS attended_exams
FROM Students
CROSS JOIN Subjects
LEFT JOIN Examinations ON
    Students.student_id = Examinations.student_id AND Subjects.subject_name =Examinations.subject_name
GROUP BY
    Students.student_id,
    Subjects.subject_name
ORDER BY
    Students.student_id,
    Subjects.subject_name;

李恒道

https://leetcode.cn/problems/confirmation-rate/submissions/595949163/?envType=study-plan-v2&envId=sql-free-50
sql也还挺有意思的

# Write your MySQL query statement below
SELECT Signups.user_id ,Round((COUNT(CASE WHEN action  = 'confirmed' THEN 1 END)/COUNT(*)),2) AS confirmation_rate  from Signups LEFT JOIN Confirmations ON Signups.user_id=Confirmations.user_id
GROUP BY Signups.user_id