51nod1294 修改数组

#include<cstdio>
#include<cstring>
#include<cctype>
#include<algorithm>
using namespace std;
#define rep(i,s,t) for(int i=s;i<=t;i++)
#define dwn(i,s,t) for(int i=s;i>=t;i--)
#define clr(x,c) memset(x,c,sizeof(x))
int read(){
	int x=0;char c=getchar();
	while(!isdigit(c)) c=getchar();
	while(isdigit(c)) x=x*10+c-‘0‘,c=getchar();
	return x;
}
const int nmax=1e5+5;
const int inf=0x7f7f7f7f;
int dp[nmax],a[nmax];
int main(){
	int n=read(),u,v,d,cnt=0,ans=0;
	rep(i,1,n){
		u=read();
		if(u-i<0) ans++;else a[++cnt]=u-i;
	}
	fill(dp+1,dp+cnt+1,inf);
	rep(i,1,cnt){
		v=upper_bound(dp+1,dp+cnt+1,a[i])-dp;dp[v]=a[i];
	}
	printf("%d\n",ans+cnt-(lower_bound(dp+1,dp+cnt+1,inf)-dp-1));
	return 0;
}