## Educational DP Contest AtCoder D - Knapsack 1

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Points: 7
Time limit: 0.25s
Python 1.0s
Memory limit: 1G

Problem type

There are items, numbered . For each , item has a weight of and a value of .

Taro has decided to choose some of the items and carry them home in a knapsack. The capacity of the knapsack is , which means that the sum of the weights of items taken must be at most .

Find the maximum possible sum of the values of items that Taro takes home.

#### Constraints

• All values in input are integers.

#### Input Specification

The first line of input will contain 2 space separated integers, and .

The next lines will contain 2 space separated integers, and , the weight and value of item .

#### Output Specification

You are to output a single integer, the maximum possible sum of the values of items that Taro takes home.

#### Sample Input 1

3 8
3 30
4 50
5 60

#### Sample Output 1

90

#### Sample Input 2

5 5
1 1000000000
1 1000000000
1 1000000000
1 1000000000
1 1000000000

#### Sample Output 2

5000000000

#### Sample Input 3

6 15
6 5
5 6
6 4
6 6
3 5
7 2

#### Sample Output 3

17

#### Sample Explanations

For the first sample, items and should be taken. Then, the sum of the weights is , and the sum of the values is .

For the second sample, it is important to note that the answer may not fit in a 32-bit integer type.

For the third sample, items , , and should be taken. Then, the sum of the weights is , and the sum of the values is .

• commented on June 13, 2022, 7:00 p.m.

Can someone have a look at my code please? I'm getting 62 test cases right, then a WA

• commented on June 13, 2022, 10:26 p.m.

try this:

1 1
1 1

correct:

1
• commented on June 14, 2022, 2:15 p.m.

thanks

• commented on July 9, 2020, 2:34 p.m.

Does anyone know why I am getting std:bad_alloc on a few cases? My code works in my IDE without any errors. Any help would be very appreciated.

• commented on July 9, 2020, 7:11 p.m.

This comment is hidden due to too much negative feedback. Show it anyway.

• commented on July 9, 2020, 7:37 p.m.

The cause of std::bad_alloc is unrelated to where the vector is located (in general, only fixed sized arrays have issues when allocated locally). The issue is that your code is exceeding the memory limit for this problem. A two dimensional vector of size -bit integers can take up to MB of storage. In addition, vector::push_back can result in the actual capacity of the vector being up to twice as large as the actual size (assuming vector::reserve is not called), thus resulting in MB of storage in the worst case.

You should aim for a solution that uses memory.