51nod 1521 一维战舰

#include<bits/stdc++.h>
using namespace std;
#define mod 1000000007
#define PI acos(-1.0)
#define INF 0x3f3f3f3f
typedef long long LL;
typedef unsigned long long ULL;

int m,n,k,a;
int q[200005];
set<int>s;

int main()
{
scanf("%d%d%d",&n,&k,&a);
scanf("%d",&m);
for(int i=1;i<=m;i++){
scanf("%d",q+i);
}
s.insert(0);
s.insert(n+1);
int ans=-1;
int num=(n+1)/(a+1);
for(int i=1;i<=m;i++){
s.insert(q[i]);
int l=*--s.find(q[i]);
int r=*++s.find(q[i]);
int t1=(r-l)/(a+1);
int t2=(q[i]-l)/(a+1)+((r-q[i])/(a+1));
//cout<<t1<<endl<<t2<<endl;
num=num-(t1-t2);
//cout<<num<<endl;
if(num<k){
ans=i;break;
}
}
printf("%d\n",ans);
return 0;
}

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<limits.h>
#include<iostream>
#include<queue>
#include<math.h>
#include<stack>
#include<vector>
#include<algorithm>
using namespace std;
#define maxn 100005
typedef long long ll;
struct node
{
ll x,y,id;
}a[maxn];
bool flag[maxn];
int  main()
{
ll n,m,i,j,k,x,y,t,ans=0;
scanf("%lld%lld%lld",&n,&x,&y);
scanf("%lld",&m);
ll num=(n+1)/(y+1);//总共能放的数量
//printf("%lld\n",num);
for(i=1;i<=m;i++)
{
scanf("%lld",&t);
flag[t]=1;
ll left=t-1,right=t+1;
while(left>=1 && flag[left]==0)
left--;
while(right<=n && flag[right]==0)
right++;
//printf("%lld %lld\n",left,right);
num-=(right-left)/(y+1)-(t-left)/(y+1)-(right-t)/(y+1);
if(num<x && ans==0)
{
ans=i;
break;
}
//printf("%lld\n",num);
}
if(ans==0)printf("-1\n");
else
printf("%lld\n",ans);
}