【当前无排名】挑战leetcode进入前1w名

李恒道

https://leetcode.cn/problems/power-of-two/submissions/569154641/?envType=study-plan-v2&envId=primers-list
基础题

func isPowerOfTwo(n int) bool {
    if(n==0){
        return false
    }
    if(n==1){
        return true
    }
    if (n<0){
        return false
    }
    for {
        var quotient = n / 2;//商
        var remainder = n % 2;//余数
        if remainder == 1{
             return false
        };
        if (quotient == 1 && remainder == 0) {
            return true
        };
        n = n / 2;
    }
}

李恒道

https://leetcode.cn/submissions/detail/569148085/
岛屿下沉问题，dfs过

var maxAreaOfIsland = function (grid) {
    const dfs = (x, y) => {
        if (x >= grid.length || x < 0 || y >= grid[0].length || y < 0) {
            return 0
        }
        if (grid[x][y] == 0) {
            return 0
        }
        grid[x][y] = 0
        return dfs(x + 1, y) + dfs(x - 1, y) + dfs(x, y + 1) + dfs(x, y - 1) + 1
    }
    let maxResult = 0
    for (let index = 0; index < grid.length; index++) {
        for (let indey = 0; indey < grid[0].length; indey++) {
            const char = grid[index][indey]
            if (char == 1) {
                const result = dfs(index, indey)
                maxResult = Math.max(maxResult, result)
            }

        }
    }
    return maxResult
};

李恒道

https://leetcode.cn/problems/power-of-three/description/?envType=study-plan-v2&envId=primers-list
秒了

func isPowerOfThree(n int) bool {
    if(n==0){
        return false
    }
    if(n==1){
        return true
    }
    if (n<0){
        return false
    }
    for {
        var quotient = n / 3;//商
        var remainder = n % 3;//余数
        if (remainder == 1||remainder == 2){
             return false
        };
        if (quotient == 1 && remainder == 0) {
            return true
        };
        n = n / 3;
    }
}

李恒道

https://leetcode.cn/problems/count-number-of-texts/description/
dfs，可以改dp

var countTexts = function (pressedKeys) {
  const cache=new Map()
  const dfs = (pos) => {
    if(cache.has(pos)){
      return cache.get(pos)
    }
    if (pos >= pressedKeys.length) {
      return 1;
    }
    const char = pressedKeys[pos];
    let result = 0;
    let maxLimt = char == "7" || char == "9" ? 4 : 3;
    let times=1;
    const oldPos=pos
    while (pressedKeys[pos] == char&&times<=maxLimt) {
      result += dfs(pos + 1);
      pos++;
      times++;
    }
    result=result% (1000000000 + 7)
    cache.set(oldPos,result)
    return result
  };
  return dfs(0);
};

李恒道

https://leetcode.cn/problems/k-radius-subarray-averages/submissions/569155028/
魔改硬凹过去的

var getAverages = function (nums, k) {
  let pos = 0;
  let result = [];
  let avergeNum = 0;
  k = k * 2 + 1;
  if(nums.length<k){
    return new Array(nums.length).fill(-1)
  }
  for (let index = 0; index < nums.length; index++) {
    const num = nums[index];
    avergeNum += num;
    pos++;
    if (pos <= k - 1) {
      continue;
    }
    result.push(Math.floor(avergeNum / k));
    avergeNum -= nums[index - k + 1];
  }
  while (result.length < nums.length) {
    if (nums.length == 1) {
      result.push(-1);
      break;
    }
    result.push(-1);
    result.unshift(-1);
  }
  return result;
};

李恒道

https://leetcode.cn/problems/minimum-recolors-to-get-k-consecutive-black-blocks/submissions/569333398/
直接灵感秒了

var minimumRecolors = function (blocks, k) {
    let pos = 0;
    let render = 0;
    let result = Number.MAX_SAFE_INTEGER
    for (let index = 0; index < blocks.length; index++) {
        const color = blocks[index];
        if (color == 'W') {
            render++;
        }
        pos++;
        if (pos < k) {
            continue;
        }
        if (blocks[index - k] == 'W') {
            render--
        }
        result = Math.min(result, render)
    }
    return result
};

李恒道

https://leetcode.cn/problems/defuse-the-bomb/submissions/569336973/
感觉秒

var decrypt = function (code, k) {
    if (k == 0) {
        return new Array(code.length).fill(0)
    }
    if (k > 0) {
        const result = new Array(code.length).fill(0)
        for (let index = 1; index <= k; index++) {
            result[0] += index < code.length ? code[index] : code[index % code.length]
        }
        for (let index = 1; index < result.length; index++) {
            const nextNum = (index + k < code.length ? code[index + k] : code[(index + k) % code.length])
            result[index] = result[index - 1] - code[index] + nextNum
        }
        return result
    }
    if (k < 0) {
        const result = new Array(code.length).fill(0)
        for (let index = 1; index <= k*-1; index++) {
            result[0] += code[code.length - index]
        }
        for (let index = 1; index < result.length; index++) {
            const nextNum = ((index + k-1) >= 0 ? code[index + k-1] : code[code.length+(index + k)-1])
            result[index] = result[index - 1] + code[index - 1] -nextNum
        }
        return result
    }
};

李恒道

https://leetcode.cn/problems/count-number-of-ways-to-place-houses/submissions/569343472/
dp秒了

var countHousePlacements = function (n) {
    const dp = new Array(n).fill(0).map(() => new Array(4).fill(0));
    dp[0][0] = 1;//不存在房屋
    dp[0][1] = 1;//存在房屋
    dp[0][2] = 1;//上存在下不存在
    dp[0][3] = 1;//上不存在下存在
    for (let index = 1; index < dp.length; index++) {
        dp[index][0] = (dp[index - 1][0] + dp[index - 1][1] + dp[index - 1][2] + dp[index - 1][3]) % (1000000000 + 7)
        dp[index][1] = dp[index - 1][0] % (1000000000 + 7)
        dp[index][2] = (dp[index - 1][3] + dp[index - 1][0]) % (1000000000 + 7)
        dp[index][3] = (dp[index - 1][2] + dp[index - 1][0]) % (1000000000 + 7)
    }
    let result = 0
    for (let index = 0; index < 4; index++) {
        result+=   dp[dp.length-1][index]

    }
    return result% (1000000000 + 7)
};

李恒道

https://leetcode.cn/problems/merge-strings-alternately/submissions/569350125/?envType=study-plan-v2&envId=programming-skills
简单题压压惊

func mergeAlternately(word1 string, word2 string) string {
    var pos int
    var result string
    for {
        if pos >= len(word1) || pos >= len(word2) {
            break
        }
        result += word1[pos:pos+1] + word2[pos:pos+1]
        pos++
    }
    if pos >= len(word1) {
        //拷贝2
        result += word2[pos:]
    } else {
        //拷贝1
        result += word1[pos:]
    }
    return result
}

李恒道

https://leetcode.cn/problems/plus-one/submissions/569353600/?envType=study-plan-v2&envId=programming-skills
有点go的感觉了
但是还是编码不规范

func plusOne(digits []int) []int {
    var pos int = len(digits) - 1
    digits[pos]++
    for {
        if digits[pos] <= 9 {
            break
        }
        digits[pos] = digits[pos] - 10
        pos--
        if pos >= 0 {
            digits[pos] += 1
        } else {
            digits = append([]int{1}, digits...)
            break
        }
    }
    return digits
}