【小米oj】 跳跳看

#define mm(a) memset(a,0,sizeof(a));
#define max(x,y) (x)>(y)?(x):(y)
#define min(x,y) (x)<(y)?(x):(y)
#define Fopen freopen("1.in","r",stdin); freopen("m.out","w",stdout);
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,b,a) for(int i=(b);i>=(a);i--)
#include<bits/stdc++.h>
typedef long long ll;
#define PII pair<ll,ll>
using namespace std;
const int INF=0x3f3f3f3f;
const int MAXN=(int)2e5 + 5;
const ll mod=1e9+7;


string input,temp;
vector<int>v;
map<int,int>mp;
int n,dp[MAXN],m,x;
int main() {
    memset(dp,INF,sizeof(dp));
    v.push_back(0);
    while(~scanf("%d",&x))v.push_back(x);
    dp[1]=0;
    n=v.size()-1;
    for(int i=1; i<=n; i++) {
        if(dp[i]==INF)continue;
        for(int j=1; j<=v[i]&&i+j<=n; j++) {
            dp[i+j]=min(dp[i+j],dp[i]+1);
        }
    }
    if(dp[n]==INF)printf("-1
");
    else printf("%d
",dp[n]);
    return 0;
}