Codeforces Gym101502 F.Building Numbers-前缀和
In this problem, you can build a new number starting from 1, by performing the following operations as much as you need:
- Add 1 to the current number.
- Add the current number to itself (i.e. multiply it by 2).
For example, you can build number 8 starting from 1 with three operations . Also, you can build number 10 starting from 1 with five operations .
You are given an array a consisting of n integers, and q queries. Each query consisting of two integers l and r, such that the answer of each query is the total number of operations you need to preform to build all the numbers in the range from l to r (inclusive) from array a, such that each number ai (l ≤ i ≤ r) will be built with the minimum number of operations.
The first line contains an integer T (1 ≤ T ≤ 50), where T is the number of test cases.
The first line of each test case contains two integers n and q (1 ≤ n, q ≤ 105), where n is the size of the given array, and q is the number of queries.
The second line of each test case contains n integers a1, a2, ..., an (1 ≤ ai ≤ 1018), giving the array a.
Then q lines follow, each line contains two integers l and r (1 ≤ l ≤ r ≤ n), giving the queries.
For each query, print a single line containing its answer.
1
5 3
4 7 11 8 10
4 5
1 5
3 3
7
18
5
As input/output can reach huge size it is recommended to use fast input/output methods: for example, prefer to use scanf/printfinstead of cin/cout in C++, prefer to use BufferedReader/PrintWriter instead of Scanner/System.out in Java.
In the first query, you need 3 operations to build number 8, and 4 operations to build number 10. So, the total number of operations is 7.
这个题要用前缀和处理一下,要不然会超时,数组开的时候注意一下,开小了,RE,很不幸,一开始没用前缀和,数组也开小了,都被卡了,(抱头痛哭)
代码:
1 //F. Building Numbers-前缀和处理,否则超时,数组开小了被卡了一手
2 #include<iostream>
3 #include<cstring>
4 #include<cstdio>
5 #include<algorithm>
6 #include<cmath>
7 using namespace std;
8 typedef long long ll;
9 const int N=1e5+10;
10 ll ans[N];
11 ll solve(ll x){
12 int num=0;
13 while(x!=1){
14 if(x%2==0)x/=2;
15 else x--;
16 num++;
17 }
18 return num;
19 }
20 int main(){
21 int t;
22 scanf("%d",&t);
23 while(t--){
24 memset(ans,0,sizeof(ans));
25 int n,m,l,r;
26 scanf("%d%d",&n,&m);
27 ll x;
28 for(int i=1;i<=n;i++){
29 scanf("%lld",&x);
30 ans[i]=ans[i-1]+solve(x);
31 }
32 for(int i=1;i<=m;i++){
33 scanf("%d%d",&l,&r);
34 printf("%lld\n",ans[r]-ans[l-1]);
35 }
36 }
37 return 0;
38 }