An array A consisting of N integers is given. The dominator of array A is the value that occurs in more than half of the elements of A.
For example, consider array A such that
A[0] = 3 A[1] = 4 A[2] = 3 A[3] = 2 A[4] = 3 A[5] = -1 A[6] = 3 A[7] = 3The dominator of A is 3 because it occurs in 5 out of 8 elements of A (namely in those with indices 0, 2, 4, 6 and 7) and 5 is more than a half of 8.
Write a function
class Solution { public int solution(int[] A); }
that, given an array A consisting of N integers, returns index of any element of array A in which the dominator of A occurs. The function should return −1 if array A does not have a dominator.
For example, given array A such that
A[0] = 3 A[1] = 4 A[2] = 3 A[3] = 2 A[4] = 3 A[5] = -1 A[6] = 3 A[7] = 3the function may return 0, 2, 4, 6 or 7, as explained above.
Write an efficient algorithm for the following assumptions:
- N is an integer within the range [0..100,000];
- each element of array A is an integer within the range [−2,147,483,648..2,147,483,647].
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int[] A) {
int value=0;
int dominator_index=-1;
int size=0;
for(int i=0; i<A.length: i++){
if(size==0){
value=A[i];
size++;
}
else{
if(value!=A[i]){
size--;
}
else{
size++;
}
}
}
int candidate=0;
if(size>0){
candidate=value;
}
int count=0;
int index=0;
for(int j:A){
if(A[j]==candidate){
count++;
index=j;
}
}
if(count>A.length/2){
dominator_index=index;
}
return dominator_index;
}
}
Solution.java:14: error: ';' expected for(int i=0; i<A.length: i++){ ^ Solution.java:14: error: ')' expected for(int i=0; i<A.length: i++){ ^ Solution.java:14: error: illegal start of expression for(int i=0; i<A.length: i++){ ^ 3 errors
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int[] A) {
int value=0;
int dominator_index=-1;
int size=0;
for(int i=0; i<A.length; i++){
if(size==0){
value=A[i];
size++;
}
else{
if(value!=A[i]){
size--;
}
else{
size++;
}
}
}
int candidate=0;
if(size>0){
candidate=value;
}
int count=0;
int index=0;
for(int j:A){
if(A[j]==candidate){
count++;
index=j;
}
}
if(count>A.length/2){
dominator_index=index;
}
return dominator_index;
}
}
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -1 at Solution.solution(Solution.java:38) at wrapper.run(wrapper.java:40) at wrapper.main(wrapper.java:29)
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int[] A) {
int value=0;
int dominator_index=-1;
int size=0;
for(int i=0; i<A.length; i++){
if(size==0){
value=A[i];
size++;
}
else{
if(value!=A[i]){
size--;
}
else{
size++;
}
}
}
int candidate=0;
if(size>0){
candidate=value;
}
int count=0;
int index=0;
for(int j=0; j<A.length; j++){
if(A[j]==candidate){
count++;
index=j;
}
}
if(count>A.length/2){
dominator_index=index;
}
return dominator_index;
}
}
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int[] A) {
int value=0;
int dominator_index=-1;
int size=0;
for(int i=0; i<A.length; i++){
if(size==0){
value=A[i];
size++;
}
else{
if(value!=A[i]){
size--;
}
else{
size++;
}
}
}
int candidate=0;
if(size>0){
candidate=value;
}
int count=0;
int index=0;
for(int j=0; j<A.length; j++){
if(A[j]==candidate){
count++;
index=j;
}
}
if(count>A.length/2){
dominator_index=index;
}
return dominator_index;
}
}
[3, 1, 5, 1, 3, 1, 1]
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int[] A) {
int value=0;
int dominator_index=-1;
int size=0;
for(int i=0; i<A.length; i++){
if(size==0){
value=A[i];
size++;
}
else{
if(value!=A[i]){
size--;
}
else{
size++;
}
}
}
int candidate=0;
if(size>0){
candidate=value;
}
int count=0;
int index=0;
for(int j=0; j<A.length; j++){
if(A[j]==candidate){
count++;
index=j;
}
}
if(count>A.length/2){
dominator_index=index;
}
return dominator_index;
}
}
[]
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int[] A) {
int value=0;
int dominator_index=-1;
int size=0;
for(int i=0; i<A.length; i++){
if(size==0){
value=A[i];
size++;
}
else{
if(value!=A[i]){
size--;
}
else{
size++;
}
}
}
int candidate=0;
if(size>0){
candidate=value;
}
int count=0;
int index=0;
for(int j=0; j<A.length; j++){
if(A[j]==candidate){
count++;
index=j;
}
}
if(count>A.length/2){
dominator_index=index;
}
return dominator_index;
}
}
[1]
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int[] A) {
int value=0;
int dominator_index=-1;
int size=0;
for(int i=0; i<A.length; i++){
if(size==0){
value=A[i];
size++;
}
else{
if(value!=A[i]){
size--;
}
else{
size++;
}
}
}
int candidate=0;
if(size>0){
candidate=value;
}
int count=0;
int index=0;
for(int j=0; j<A.length; j++){
if(A[j]==candidate){
count++;
index=j;
}
}
if(count>A.length/2){
dominator_index=index;
}
return dominator_index;
}
}
[0, 1, 0]
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int[] A) {
int value=0;
int dominator_index=-1;
int size=0;
for(int i=0; i<A.length; i++){
if(size==0){
value=A[i];
size++;
}
else{
if(value!=A[i]){
size--;
}
else{
size++;
}
}
}
int candidate=0;
if(size>0){
candidate=value;
}
int count=0;
int index=0;
for(int j=0; j<A.length; j++){
if(A[j]==candidate){
count++;
index=j;
}
}
if(count>A.length/2){
dominator_index=index;
}
return dominator_index;
}
}
[0, 1, 0]
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int[] A) {
int value=0;
int dominator_index=-1;
int size=0;
for(int i=0; i<A.length; i++){
if(size==0){
value=A[i];
size++;
}
else{
if(value!=A[i]){
size--;
}
else{
size++;
}
}
}
int candidate=0;
if(size>0){
candidate=value;
}
int count=0;
int index=0;
for(int j=0; j<A.length; j++){
if(A[j]==candidate){
count++;
index=j;
}
}
if(count>A.length/2){
dominator_index=index;
}
return dominator_index;
}
}
The solution obtained perfect score.