An integer is divisible by 3 if the sum of its digits is also divisible by 3. for example, 3702 is divisible by 3 and 12 (3 + 7 + 0 + 2) is also divisible by 3. this property also holds for the integer 9.
In this problem, we will investigate this property for other integers.
Input
Input starts with an integerT (≤ 200), Denoting the number of test cases.
Each case contains three positive integersA, BAndK (1 ≤ A ≤ B <231 and 0 <K <10000).
Output
For each case, output the case number and the number of integers in the range[A, B]Which are divisibleKAnd the sum of its digits is also divisibleK.
| Sample Input |
Output for Sample Input |
3 1 20 1 1 20 2 1 1000 4 |
Case 1: 20 Case 2: 5 Case 3: 64
|
When the array is enabled, dp [12] [10010] [90] will pop up the memory.
Considering that no DP is needed as long as K> = 90 (the sum of single digits cannot exceed 90)
Therefore, you only need to open the array to dp [12] [90] [90].
#include
#include
#include
#include
using namespace std;typedef long long ll;ll dp[12][90][90];vector
digit;ll m,n,k;ll dfs(int pos,int mod,int sum,int done){ if(pos==-1) return sum==0&&mod==0; if(!done && ~dp[pos][mod][sum]) return dp[pos][mod][sum]; ll res = 0; int end = done?digit[pos]:9; for(int i = 0; i <= end; i++){ res += dfs(pos-1,(mod*10+i)%k,(sum+i)%k,done&&i==end); } if(!done) dp[pos][mod][sum] = res; return res;}ll solve(ll x){ digit.clear(); while(x){ digit.push_back(x%10); x /= 10; } return dfs(digit.size()-1,0,0,1);}int main(){ int ncase,T=1; cin >> ncase; while(ncase--){ cin >> m >> n >> k; if(k >= 90){ printf("Case %d: 0\n",T++); continue; } memset(dp,-1,sizeof dp); printf("Case %d: %d\n",T++,solve(n)-solve(m-1)); } return 0;}