题目链接
1 #include<bits/stdc++.h>
2 using namespace std;
3 #define mem1(a) memset(a, -1, sizeof(a))
4 #define ll long long
5 int dp[20][20], digit[20], len;
6 ll dfs(int len, int pre, bool fp, bool first) { //first表示前面的数是否全部为0， pre是前一个数
7 if(!len)
8 return 1;
9 if(!first&&!fp && dp[len][pre]!=-1)
10 return dp[len][pre];
11 int ret = 0, maxx = fp?digit[len]:9;
12 for(int i = 0; i<=maxx; i++) {
13 if(!first)
14 if(abs(i-pre)<2)
15 continue;
16 ret += dfs(len-1, i, fp&&i == maxx, first&&i==0);
17 }
18 if(!fp&&!first)
19 return dp[len][pre] = ret;
20 return ret;
21 }
22 int cal(int n) {
23 len = 0;
24 while(n) {
25 digit[++len] = n%10;
26 n/=10;
27 }
28 return dfs(len, 0, true, true);
29 }
30 int main()
31 {
32 int a, b;
33 mem1(dp);
34 while(~scanf("%d%d", &a, &b)) {
35 printf("%d\n", cal(b)-cal(a-1));
36 }
37 }
