#include <bits/stdc++.h> using namespace std; #define rep(i,a,n) for (int i=a;i<n;i++) #define per(i,a,n) for (int i=n-1;i>=a;i--) #define pb push_back #define mp make_pair #define all(x) (x).begin(),(x).end() #define fi first #define se second #define SZ(x) ((int)(x).size()) typedef vector<int> VI; typedef long long ll; typedef pair<int,int> PII; typedef double db; const ll mod=1000000007; ll powmod(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;} ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;} // head char s[30]; ll dp[30]; int main() { scanf("%s",s+1); int n=strlen(s+1); dp[0]=1; rep(i,1,n+1) { int f=s[i]-'0'; dp[i]+=dp[i-1]*(f+1); if (i>=2&&s[i-1]=='1') dp[i]+=dp[i-2]*(9-f); } printf("%lld\n",dp[n]); }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 | #include <bits/stdc++.h> using namespace std; #define rep(i,a,n) for (int i=a;i<n;i++) #define per(i,a,n) for (int i=n-1;i>=a;i--) #define pb push_back #define mp make_pair #define all(x) (x).begin(),(x).end() #define fi first #define se second #define SZ(x) ((int)(x).size()) typedef vector<int> VI; typedef long long ll; typedef pair<int,int> PII; typedef double db; const ll mod=1000000007; ll powmod(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;} ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;} // head char s[30]; ll dp[30]; int main() { scanf("%s",s+1); int n=strlen(s+1); dp[0]=1; rep(i,1,n+1) { int f=s[i]-'0'; dp[i]+=dp[i-1]*(f+1); if (i>=2&&s[i-1]=='1') dp[i]+=dp[i-2]*(9-f); } printf("%lld\n",dp[n]); } |