【小米oj】 国王招驸马

基础dp

#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;
int main() {
    while(cin>>input) {
        istringstream iss(input);
        memset(dp,INF,sizeof(dp));
        v.clear();
        v.push_back(0);
        while (getline(iss, temp, ',')) {
            int x=atoi(temp.c_str());
            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;
}