Codeforces 758D Ability To Convert dp

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define MS(a) memset(a,0,sizeof(a))
#define MP make_pair
#define PB push_back
const int INF = 0x3f3f3f3f;
const ll INFLL = 0x3f3f3f3f3f3f3f3fLL;
inline ll read(){
    ll x=0,f=1;char ch=getchar();
    while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}
    while(ch>=‘0‘&&ch<=‘9‘){x=x*10+ch-‘0‘;ch=getchar();}
    return x*f;
}
//////////////////////////////////////////////////////////////////////////
const int maxn = 1e5+10;

ll n;
char s[100];
unsigned long long dp[100];

int main(){
    cin >> n >> s+1;
    for(int i=0; i<100; i++) dp[i]=INFLL;
    dp[0] = 0;
    int len = strlen(s+1);

    for(int i=1; i<=len; i++){
        ll t = 0;
        for(int j=i; j<=len; j++){
            t = t*10+(s[j]-‘0‘);
            if(t >= n) break;
            if(s[i]==‘0‘) { dp[j] = min(dp[j],dp[i-1]*n); break;}
            else dp[j] = min(dp[j],dp[i-1]*n+t);
        }
    }
    cout << dp[len] << endl;

    return 0;
}