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# Find the maximum product of 3 integers in a list

The following code handles negatives as well.

Time Complexity O(n)
Space Complexity O(1)

Code

```package algos;

public class maxThreeProd {
public static int maxThree(int[] input) {
if (input.length <= 3) {
int ret = 1;
for (int i = 0; i < input.length; i++) {
ret *= input[i];
}
return ret;
}

int m1 = Integer.MIN_VALUE;
int m2 = Integer.MIN_VALUE;
int m3 = Integer.MIN_VALUE;
int l1 = Integer.MAX_VALUE;
int l2 = Integer.MAX_VALUE;
for (int i = 0; i < input.length; i++) { if (input[i] > m1) {
m3 = m2;
m2 = m1;
m1 = input[i];
} else if (input[i] > m2) {
m3 = m2;
m2 = input[i];
} else if (input[i] > m3) {
m3 = input[i];
}

if (input[i] < l1) {
l2 = l1;
l1 = input[i];
} else if (input[i] < l2) {
l2 = input[i];
}
}

return Math.max(l1 * l2 * m3, m1 * m2 * m3);

}

public static void main(String[] args) {
int[] input = { 1, 5, 3, 2 };
if (input.length == 0)
System.out.println("null");
else
System.out.println(maxThree(input));
}
}
```

Output

`30`