input:lucky.in output:lucky.out
时间限制: 2000 ms 空间限制: 256000 KB 具体限制
1 #include <bits/stdc++.h> 2 using namespace std; 3 int readint() { 4 int x = 0; 5 char c = getchar(); 6 for (; c < '0' || c > '9'; c = getchar()); 7 for (; c >= '0' && c <= '9'; c = getchar()) x = (x * 10) + (c - '0'); 8 return x; 9 } 10 long long toVal(string s) { 11 long long sum = 0; 12 for (int i = 0; s[i]; ++i) 13 sum = (sum * 10) + (s[i] - '0'); 14 return sum; 15 } 16 const int MAXN = 170000 + 5; 17 int x, y, hd, tl, len, ans; 18 string s, d[MAXN]; 19 void dfs(int pos) 20 { 21 long long tmp = 0; 22 if (pos == len) 23 { 24 tmp = toVal(s); 25 int addnum = 0; 26 for (; tmp <= y;) 27 { 28 d[++tl] = s; 29 if (tmp >= x && tmp <= y) ++ans; 30 31 s = s[0] + s; 32 ++addnum; 33 tmp = toVal(s); 34 } 35 s.erase(0, addnum); 36 return; 37 } 38 tmp = (s[pos] - '0') + (d[hd][pos] - '0'); 39 if (tmp <= 9) 40 { 41 s += (char)(tmp + '0'); 42 dfs(pos + 1); 43 s.erase(pos + 1, 1); 44 } 45 tmp = s[pos] - d[hd][pos]; 46 if (tmp >= 0 && d[hd][pos] != '0') 47 { 48 s += (char)(tmp + '0'); 49 dfs(pos + 1); 50 s.erase(pos + 1, 1); 51 } 52 } 53 int main() 54 { 55 freopen("lucky.in", "r", stdin); 56 freopen("lucky.out", "w", stdout); 57 x = readint(); 58 y = readint(); 59 d[tl = 1] = "7"; 60 if (x <= 7 && y >= 7) ++ans; 61 for (; hd < tl;) 62 { 63 len = d[++hd].size(); 64 for (char c = '1'; c <= '9'; ++c) { 65 s = c; 66 dfs(0); 67 } 68 } 69 printf("%d ", ans); 70 fclose(stdin); 71 fclose(stdout); 72 return 0; 73 }