【当前无排名】挑战leetcode进入前1w名

李恒道

王一之 发表于 2024-9-16 03:19
nb 都13页了

115题了
还是没进10w
好像现在需要差不多250-300才能有排名
太恐怖了

李恒道

https://leetcode.cn/problems/next-permutation/submissions/565262238/?envType=study-plan-v2&envId=top-100-liked
纯记忆的规则题
感觉都没什么学的必要...

const swap = (arr, x, y) => {
    arr[x] ^= arr[y]
    arr[y] ^= arr[x]
    arr[x] ^= arr[y]
}
var nextPermutation = function (nums) {
    let hasNum = undefined
    for (let index = nums.length - 2; index >= 0; index--) {
        const num = nums[index];
        const nextNum = nums[index + 1];
        if (num < nextNum) {
            hasNum = index;
            break;
        }
    }
    if (hasNum!==undefined) {
        for (let index = nums.length - 1; index > hasNum; index--) {
            const num = nums[index];
            if (num > nums[hasNum]) {
                swap(nums, hasNum, index)
                break;
            }
        }
        const times = Math.floor((nums.length - hasNum - 1) / 2);
        for (let index = hasNum + 1; index <= times + hasNum; index++) {
            swap(nums, index, nums.length - (index - hasNum))
        }
    } else {
        nums.reverse()
    }
};

李恒道

https://leetcode.cn/problems/n-th-tribonacci-number/?envType=study-plan-v2&envId=dynamic-programming
斐波那契数列
按道理应该也有齐次方程吧
懒得推了

var tribonacci = function (n) {
  const arr = [0, 1, 1];
  if(n<=2){
    return arr[n]
  }
  for (let index = 3; index <= n; index++) {
    let num = arr[0] + arr[1] + arr[2];
    arr.shift()
    arr.push(num)
  }
  return arr.pop();
};    

李恒道

https://leetcode.cn/problems/min-cost-climbing-stairs/submissions/565511955/?envType=study-plan-v2&envId=dynamic-programming
一波秒！

var minCostClimbingStairs = function (cost) {
  const dp = new Array(cost.length);
  dp[dp.length - 1] = cost[cost.length - 1];
  dp[dp.length - 2] = cost[cost.length - 2];
  for (let index = cost.length - 3; index >= 0; index--) {
    dp[index] = cost[index] + Math.min(dp[index + 1], dp[index + 2]);
  }
  return Math.min(dp[0], dp[1]);
};

李恒道

https://leetcode.cn/problems/delete-and-earn/submissions/565569533/?envType=study-plan-v2&envId=dynamic-programming
秒了

var deleteAndEarn = function (nums) {
    const newNum = []
    const countCache = new Map()
    for (let index = 0; index < nums.length; index++) {
        const num = nums[index];
        if (countCache.has(num)) {
            countCache.set(num, countCache.get(num) + 1)
        } else {
            newNum.push(num)
            countCache.set(num, 1)
        }
    }
    newNum.sort((a, b) => a - b)
    newNum.push(0)
    newNum.push(0)
    const dp = new Array(newNum.length + 2).fill(0)

    for (let index = newNum.length - 3; index >= 0; index--) {
        const num = newNum[index];
        dp[index] = newNum[index] * countCache.get(newNum[index])
        if (newNum[index + 1] == num + 1) {
            dp[index] += dp[index + 2]
            dp[index] = Math.max(dp[index], dp[index + 1])
        } else {
            dp[index] += dp[index + 1]
        }
    }
    return Math.max(dp[0],dp[1])

};

李恒道

https://leetcode.cn/problems/unique-paths-ii/submissions/565578976/?envType=study-plan-v2&envId=dynamic-programming

基础dp，秒了

var uniquePathsWithObstacles = function (obstacleGrid) {
    if(obstacleGrid[obstacleGrid.length-1][obstacleGrid[0].length - 1]==1){
        return 0
    }

    const dp = new Array(obstacleGrid.length + 1).fill(0).map(() => new Array(obstacleGrid[0].length + 1).fill(0))
    dp[obstacleGrid.length-1][obstacleGrid[0].length - 1]=1
    for (let index = obstacleGrid.length - 1; index >= 0; index--) {
        for (let indey = obstacleGrid[0].length - 1; indey >= 0; indey--) {
            if( index==obstacleGrid.length-1&&indey==obstacleGrid[0].length - 1){
                continue;
            }
            if (obstacleGrid[index][indey] == 1) {
                dp[index][indey] = 0
                continue;
            }
            const down = dp[index + 1][indey]
            const right = dp[index][indey + 1]
            dp[index][indey] = down + right
        }
    }
    return dp[0][0]
};

wuxin0011

厉害，ggnb

李恒道

wuxin0011 发表于 2024-9-18 07:49
厉害，ggnb

哥哥要不也开个贴一起玩
当打发时间了
多个人我也有危机感

wuxin0011

李恒道 发表于 2024-9-18 08:53
哥哥要不也开个贴一起玩
当打发时间了
多个人我也有危机感

这是我LC主页： https://leetcode.cn/u/agitated-curranfnd/

wuxin0011

刷题也就图一乐