AllZeroSequence

You are given a sequence $A{}$ consisting of $N{}$ integers $A_1,A_2,...,A_N$ . You can perform some operations on the sequence.

In one operation, you should do the following steps in order :

Choose an integer $i{}$ such that $1\leq i\leq N$ and $A_i>0$ , then decrease $A_i$ . Decrease $A_i$ means changing $A_i$ to $A_i-1$ .
For all integer $j{}$ such that $1\leq j\leq N$ and $A_j>1$ , decrease $A_j$ .

For example, $A=[1,2,3]{}$ . In one operations, if you choose $i=3{}$ . After the first step, $A{}$ becomes $[1,2,2]{}$ . After the second step, $A{}$ becomes $[1,1,1]{}$ .

Now you are given an integer $K{}$ , your task is to determine if it is possible to make the sequence $A{}$ consists of $N{}$ zeros in no more than $K{}$ operations.

#include<bits/stdc++.h> using namespace std; int n,k,a[200010]; int main(){ scanf("%d%d",&n,&k); for(int i=1;i<=n;i++) scanf("%d",&a[i]); sort(a+1,a+1+n); int s=k-n; for(int i=1;i<=n;i++){ if(a[i]-i-(k-n)>0) s-=a[i]-i-(k-n); if(s<0) return printf("No"),0; } printf("Yes"); return 0; }

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