[leetcode weekly replay] 303rd weekly 20220724

One 、 Summary of this week's race

• A week of losing points .
• The first three questions are hard to do very quickly , Question 4: sitting and wearing at the bottom of the prison .
  

Two 、 [Easy] 6124. The first letter that appears twice

link : 6124. The first letter that appears twice

1. Title Description

2. Thought analysis

grading Easy.
According to the meaning of the question .

3. Code implementation

class Solution:
    def repeatedCharacter(self, s: str) -> str:
        cnt = defaultdict(int)
        for c in s:
            cnt[c]+= 1
            if cnt[c] == 2:
                return c
        

3、 ... and 、[Medium] 6125. Equal row and column pairs

link : 6125. Equal row and column pairs

1. Title Description

2. Thought analysis

grading Medium.
Violent judgment after transposition .

3. Code implementation

class Solution:
    def equalPairs(self, grid: List[List[int]]) -> int:
        n = len(grid)
        
        g = [[0]*n for i in range(n)]
        for i in range(n):
            for j in range(n):
                g[j][i] = grid[i][j]
        
        
        ans = 0
        for i in range(n):
            for j in range(n):
                if g[i] == grid[j]:
                    ans += 1
        return ans

Four 、[Medium] 6092. Replace elements in an array

link : 6092. Replace elements in an array

1. Title Description

2. Thought analysis

grading Medium.
And the biweekly match last night T3 almost , Namely k,v Mutual hash of .

3. Code implementation

class FoodRatings:

    def __init__(self, foods: List[str], cuisines: List[str], ratings: List[int]):
        self.f_c = defaultdict()
        self.f_r = defaultdict()
        from sortedcontainers import SortedList
        self.c_rf = defaultdict(SortedList)
        c_rf = self.c_rf
        f_c = self.f_c
        f_r = self.f_r
        n = len(foods)
        for f,c,r in zip(foods,cuisines,ratings):
            c_rf[c].add((-r,f))
            f_c[f] = c 
            f_r[f] = r

    def changeRating(self, food: str, newRating: int) -> None:
        c_rf = self.c_rf
        f_c = self.f_c
        f_r = self.f_r
        f = food
        c = f_c[food]
        r = f_r[food]
        c_rf[c].remove((-r,f))
        r = newRating
        c_rf[c].add((-r,f))
        f_c[f] = c 
        f_r[f] = newRating
        # print(c_rf)
        
    def highestRated(self, cuisine: str) -> str:
        return self.c_rf[cuisine][0][1]

# Your FoodRatings object will be instantiated and called as such:
# obj = FoodRatings(foods, cuisines, ratings)
# obj.changeRating(food,newRating)
# param_2 = obj.highestRated(cuisine)

5、 ... and 、[Hard] 6127. The number of high-quality pairs

link : 6127. The number of high-quality pairs

1. Title Description

2. Thought analysis

grading Hard.
Be in jail .

• Actually found a&b and a|b Bit 1 Sum of numbers =a The number of +b The number of .
• So count the bits of each number 1 Number , The sum calculated after sorting is greater than k Logarithm of .

3. Code implementation

class Solution:
    def countExcellentPairs(self, nums: List[int], k: int) -> int:
        """ 001 010 011 001 101 001 001 """
        nums = sorted(list(set(nums)))
        def hammingWeight( n: int) -> int:
            ret = 0
            while n:
                n &= n - 1
                ret += 1
            return ret
        arr = []
        for a in nums:
            arr.append(hammingWeight(a))
        arr.sort()
        n = len(arr)
        ans = 0
        for i,a in enumerate(arr):
            j = bisect_left(arr,k-a)
            ans += n-j
        return ans