Codeforces 11.02

1.https://codeforces.com/contest/2036/problem/B
一道很简单的模拟题，直接模拟即可

代码附上:

    *for _ in range(int(input())):
	  n,k = map(int,input().split())
	  a = [0]*k
	  while k:
		  x,y = map(int,input().split())
		  a[x-1] += y
		  k -= 1
	  print(sum(sorted(a)[-n:]))*

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2.https://codeforces.com/contest/2036/problem/C
这道题目直接每改一次元素的值便查询一次是，会超时的。对一个位置i来说，它对_1100_来说影响的只有i -3 到i + 3*,附上代码:

  for _ in range(int(input())):
      s = input().strip(); n = len(s); S = [''] + list(s)
      c = sum(1 for j in range(1, n - 2) if S[j:j + 4] == ['1', '1', '0', '0'])
      for _ in range(int(input())):
          i, v = map(int, input().split())
          for j in range(i - 3, i + 1):
              if 1 <= j <= n - 3: c -= (S[j:j + 4] == ['1', '1', '0', '0'])
          S[i] = str(v)
          for j in range(i - 3, i + 1):
                if 1 <= j <= n - 3: c += (S[j:j + 4] == ['1', '1', '0', '0'])
          print("YES" if c > 0 else "NO")