Merge pull request #9 from pedroulissespu/master

lol

kekw.cpp

@@ -0,0 +1,45 @@
+#include "bits/stdc++.h"
+using namespace std;
+
+int dp[20][200][2];
+
+int digitDP(int idx, int sum, int can, vector<int> &digit)
+{// idx eh o indice atual, sum a soma dos digitos ate idx, 
+//e can uma flag para indicar se pode colocar 
+//qualquer valor a partir daqui
+	if(idx == (int)digit.size()) 
+		return sum;
+	if(dp[idx][sum][can] != -1)
+		return dp[idx][sum][can];
+	int ans = 0;
+	for(int i = 0; i < 10; i++)
+		if(can or i <= digit[idx])
+			ans += digitDP(idx + 1, sum + i, 
+				can or i < digit[idx], digit);
+	return dp[idx][sum][can] = ans;
+}
+
+int query(int x) // responde a consulta de 0 ate x
+{
+	memset(dp, -1, sizeof(dp));	
+    vector<int> digit;
+    while(x)
+    {
+        digit.push_back(x%10);
+        x /= 10;
+    }
+    reverse(digit.begin(), digit.end());
+    return digitDP(0, 0, 0, digit);
+}
+
+int main()
+{
+    int q, a, b;
+    cin >> q;
+    while(q--)
+    {
+		cin >> a >> b;
+		cout << query(b) - query(a - 1) << '\n';
+	}
+    return 0;
+}