题意：https://nanti.jisuanke.com/t/41422
对每一位进行找循环节规律就行了。
1 #define IOS ios_base::sync_with_stdio(0); cin.tie(0); 2 #include <cstdio>//sprintf islower isupper 3 #include <cstdlib>//malloc exit strcat itoa system("cls") 4 #include <iostream>//pair 5 #include <fstream>//freopen("C:\Users\13606\Desktop\草稿.txt","r",stdin); 6 #include <bitset> 7 //#include <map> 8 //#include<unordered_map> 9 #include <vector> 10 #include <stack> 11 #include <set> 12 #include <string.h>//strstr substr 13 #include <string> 14 #include <time.h>//srand(((unsigned)time(NULL))); Seed n=rand()%10 - 0~9; 15 #include <cmath> 16 #include <deque> 17 #include <queue>//priority_queue<int, vector<int>, greater<int> > q;//less 18 #include <vector>//emplace_back 19 //#include <math.h> 20 //#include <windows.h>//reverse(a,a+len);// ~ ! ~ ! floor 21 #include <algorithm>//sort + unique : sz=unique(b+1,b+n+1)-(b+1);+nth_element(first, nth, last, compare) 22 using namespace std;//next_permutation(a+1,a+1+n);//prev_permutation 23 #define rint register int 24 #define fo(a,b,c) for(rint a=b;a<=c;++a) 25 #define fr(a,b,c) for(rint a=b;a>=c;--a) 26 #define mem(a,b) memset(a,b,sizeof(a)) 27 #define pr printf 28 #define sc scanf 29 #define ls rt<<1 30 #define rs rt<<1|1 31 typedef long long ll; 32 void swapp(int &a,int &b); 33 double fabss(double a); 34 int maxx(int a,int b); 35 int minn(int a,int b); 36 int Del_bit_1(int n); 37 int lowbit(int n); 38 int abss(int a); 39 const double E=2.718281828; 40 const double PI=acos(-1.0); 41 //const ll INF=(1LL<<60); 42 const int inf=(1<<30); 43 const double ESP=1e-9; 44 const int mod=(int)1e9+7; 45 const int N=(int)1e6+10; 46 47 int ans[12][60]; 48 ll m[20]={0,0,1,3,6,10,15,21,28,36,45}; 49 50 int geet(int n,int b) 51 { 52 int sum=0; 53 while(n>0) 54 { 55 sum+=n%b; 56 n/=b; 57 } 58 return sum; 59 } 60 61 ll get(ll n,ll b) 62 { 63 ll temp=n; 64 int l=0; 65 while(temp>0) 66 { 67 temp/=b; 68 l++; 69 } 70 ll sum=0; 71 ll val[60]; 72 val[l]=1; 73 n++; 74 for(int i=l-1;i>=1;--i) 75 val[i]=val[i+1]*b; 76 for(int i=1;i<=l;++i) 77 { 78 ll LOOP=n/(val[i]*b); 79 sum+=LOOP*m[b]*val[i]; 80 ll len=n%(val[i]*b); 81 int start=0; 82 while(len>=val[i]) 83 { 84 sum+=start*val[i]; 85 start++; 86 len-=val[i]; 87 } 88 sum+=len*start; 89 } 90 return sum; 91 } 92 93 int main() 94 { 95 int T,cont=0; 96 sc("%d",&T); 97 while(T--) 98 { 99 ll n;int b; 100 sc("%lld%d",&n,&b); 101 for(int i=2;i<=10;++i) 102 { 103 ans[i][1]=1; 104 for(int j=2;j<=45;++j) 105 ans[i][j]=ans[i][j-1]*b; 106 } 107 // for(int i=1;i<=100;++i) 108 // pr("%lld ",get(i,2)); 109 pr("Case #%d: %lld ",++cont,get(n,b)); 110 } 111 return 0; 112 } 113 114 /**************************************************************************************/ 115 116 int maxx(int a,int b) 117 { 118 return a>b?a:b; 119 } 120 121 void swapp(int &a,int &b) 122 { 123 a^=b^=a^=b; 124 } 125 126 int lowbit(int n) 127 { 128 return n&(-n); 129 } 130 131 int Del_bit_1(int n) 132 { 133 return n&(n-1); 134 } 135 136 int abss(int a) 137 { 138 return a>0?a:-a; 139 } 140 141 double fabss(double a) 142 { 143 return a>0?a:-a; 144 } 145 146 int minn(int a,int b) 147 { 148 return a<b?a:b; 149 }