javacoder1's blog

DP SOLUTION NEEDED!!
By javacoder1, history, 7 years ago, In English

You have a string of length 10^5 which is a binary representation of a number.The string has no leading zeros like 11001 represent the number 25. We have to represent it as sum of numbers of the form of 2^x or -2^x (x>=0) . Find the minimum number of numbers needed to do so. Please highlight the states you use and the transitions when replying !

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7 years ago, # |
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A binary number can be converted to a decimal by using the following formula: \sum_{i=0}^n a_i2^{n-i} Where a is the binary representation of the number. Therefore a simple solution is this: 

printf("2^%d", n);
for(int i = 1; i < n; i++) {
  if(a[i] == '1') {
    printf("+2^%d", n - i);
  }
}
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    7 years ago, # ^ |
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    You didn't understand the problem. For example, take 7. The answer isn't 1+2+4, it is 8-1

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7 years ago, # |
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http://codeforces.com/contest/132/problem/D

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    7 years ago, # ^ |
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    Can you explain the dp part , i read the editorial but could not get it properly.

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