#include <iostream>
#define pb push_back
#define s second
#define f first
#define ll long long
using namespace std;
string str;
int dp[15][15][25][5],SIZE;
int get(int last2,int last,int len,int sm){
if (len >= SIZE) return 1;
if (dp[last2][last][len][sm] != -1)
return dp[last2][last][len][sm];
int l = str[len] - '0',sum = 0;
if (sm){
for (int i = 0; i <= 9; i++){
if (i != last && i != last2)
sum += get(last,i,len + 1,1);
}
}
else{
for (int i = 0; i < l; i++){
if (i != last && i != last2)
sum += get(last,i,len + 1,1);
}
if (l != last && l != last2)
sum += get(last,l,len + 1,0);
}
return dp[last2][last][len][sm] = sum;
}
void clear(){
for (int i = 0; i <= 9; i++)
for (int j = 0; j <= 9; j++)
for (int z = 0; z<=20; z++)
dp[i][j][z][0] = dp[i][j][z][1] = -1;
}
int G(int x){
if (x < 0) return 0;
clear();
str = "";
while(x){
str+=(x%10)+'0';
x/=10;
}
reverse(str.begin(),str.end());
int l = str[0] - '0',ans = 0;
SIZE = str.size();
for (int i = 1; i < l; i++)
ans += get(i,i,1,1);
ans += get(l,l,1,0);
clear();
for (int i = 2; i < str.size() - 1; i++)
SIZE = i;
for (int j = 1; j <= 9; j++)
ans += get(j,j,1,1);
return ans;
}
signed main (){
ios_base::sync_with_stdio(0),cin.tie(NULL),cout.tie(NULL);
freopen("output.txt", "w", stdout);
ll a,b;
cin>>a>>b;
cout<<G(b) - G(a - 1)<<"\n";
}
Compilation message
numbers.cpp: In function 'int G(int)':
numbers.cpp:49:5: error: 'reverse' was not declared in this scope
49 | reverse(str.begin(),str.end());
| ^~~~~~~
numbers.cpp:57:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
57 | for (int i = 2; i < str.size() - 1; i++)
| ~~^~~~~~~~~~~~~~~~
numbers.cpp:57:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
57 | for (int i = 2; i < str.size() - 1; i++)
| ^~~
numbers.cpp:59:9: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
59 | for (int j = 1; j <= 9; j++)
| ^~~
numbers.cpp: In function 'int main()':
numbers.cpp:65:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
65 | freopen("output.txt", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
