C++ 解法, 执行用时: 6ms, 内存消耗: 3648KB, 提交时间: 2020-07-28

#include <bits/stdc++.h>
using namespace std;
     
#define gc() (p1==p2&&(p1=bf,p2=bf+fread(bf,1,1<<24,stdin),p1==p2)?EOF:*p1++)
char bf[1<<24], *p1=bf, *p2=bf;
template<class T> void read(T& x) {
    char c(gc()); T t(0);
    for (; c != EOF && !isdigit(c); c = gc());
    for (; isdigit(c); c = gc()) t = 10 * t + (c & 15);
    x = t;
}
     
int main() {
    int n,k,x,c(0);
    vector<int> vv;
    read(n);
    read(k);
    for(int i =0;i<n;++i){
        read(x);
        if(!x){
            vv.push_back(i);
            c++;
        }
    }
    vv.push_back(n);
    if(c<k)k = c;
    int ans = vv[k];
         
    for(int i = k + 1;i<vv.size();++i){
        ans = max(ans,vv[i] - vv[i-k-1] - 1);
    }
    cout<<ans<<endl;
}

C++14 解法, 执行用时: 7ms, 内存消耗: 3160KB, 提交时间: 2020-05-20

#include <bits/stdc++.h>
using namespace std;
    
#define gc() (p1==p2&&(p1=bf,p2=bf+fread(bf,1,1<<24,stdin),p1==p2)?EOF:*p1++)
char bf[1<<24], *p1=bf, *p2=bf;
template<class T> void read(T& x) {
    char c(gc()); T t(0);
    for (; c != EOF && !isdigit(c); c = gc());
    for (; isdigit(c); c = gc()) t = 10 * t + (c & 15);
    x = t;
}
    
int main() {
    int n,k,x,c(0);
    vector<int> vv;
    read(n);
    read(k);
    for(int i =0;i<n;++i){
        read(x);
        if(!x){
            vv.push_back(i);
            c++;
        }
    }
    vv.push_back(n);
    if(c<k)k = c;
    int ans = vv[k];
        
    for(int i = k + 1;i<vv.size();++i){
        ans = max(ans,vv[i] - vv[i-k-1] - 1);
    }
    cout<<ans<<endl;
}