Submission #623819

#	Time	Username	Problem	Language	Result	Execution time	Memory
623819		a_aguilo	Mutating DNA (IOI21_dna)	C++17	0 / 100	29 ms	5420 KiB

dna

#include "dna.h"
#include<bits/stdc++.h>

using namespace std;

vector<int> tree;
int n;

void buildTree (int node, int left, int right, int arr[]){
    if(left > right) return;
    if(left == right){
        tree[node] = arr[left];
        return;
    }
    int mid = left + (right - left)/2;
    buildTree(2*node, left, mid, arr);
    buildTree(2*node+1, mid+1, right, arr);
    tree[node] = tree[2*node] + tree[2*node+1];
}

int getValue (int node, int left, int right, int x, int y){
    if(x > right or y < left) return 0;
    if(x <= left and y >= right) return tree[node];
    int mid = left + (right - left)/2;
    return getValue(2*node, left, mid, x, y)+getValue(2*node+1, mid+1, right, x, y);
}

void init(string a, string b) {
    n = a.size();
    int arr[a.size()];
    for (int i = 0; i < a.size(); ++i){
        if(a[i] == b[i])arr[i] = 0;
        else arr[i] = 1;
    }
    tree = vector<int> (4*a.size(), 0);
    buildTree(1, 0, a.size()-1, arr);
}

int get_distance(int x, int y) {
	int n = getValue(1, 0, n-1, x, y);
	if(n%2 != 0) return -1;
	else return n/2;
}

Compilation message (stderr)

dna.cpp: In function 'void init(std::string, std::string)':
dna.cpp:31:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |     for (int i = 0; i < a.size(); ++i){
      |                     ~~^~~~~~~~~~
dna.cpp: In function 'int get_distance(int, int)':
dna.cpp:40:18: warning: 'n' is used uninitialized in this function [-Wuninitialized]
   40 |  int n = getValue(1, 0, n-1, x, y);
      |          ~~~~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 21
• Subtask 2: 0 / 22
• Subtask 3: 0 / 13
• Subtask 4: 0 / 28
• Subtask 5: 0 / 16