# 11th question: Remove repeated elements from the array and remove the Array

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11th question: Remove repeated elements from the array and remove the Array
/* I climbed to Taishan a few days ago, but I haven't updated it all the time. I still don't feel much about it when I went up the hill. I am about to crash after going down the hill. My bones are scattered and I will continue to update my bones ......*/Question: Remove repeated elements from the array

Given an array in ascending order, remove the number of duplicates and return the length of the new array.

For example:

Array A = {1, 1, 2}, your function should return length 2, new array is {1, 2}

Requirements:

You cannot create an array to allocate additional space. That is, the constant space limit.

Tip:

Input an integer n and its corresponding array A [n], and output the length of the new array.

Sample Input

`50 0 1 1 2`

Sample output

`3`

Resolution:
`# Include <stdio. h> int main () {/* I is the cyclic variable, n and A [] are the requirements of the question, temp is A temporary value, compare the stored values with A [I + 1]. If they are equal, leave the next value empty. Otherwise, assign A [I + 1] value to tempcount as the number of null values, subtracting the number of null values from the original array is the new array length */int I, n, A [1000], temp, count = 0; scanf ("% d ", & n); for (I = 0; I <n; I ++) {scanf ("% d", & A [I]);} temp = A [0]; for (I = 1; I <n; I ++) {if (A [I] = temp) {A [I] = ''; count ++;} elsetemp = A [I];} printf (" % d \ n ", n-count); return 0 ;}`

C language, delete repeated elements in the array

# Include <stdio. h>
# Define N 1000
# Define FLAG 0x80000000/* special mark, expressed with the smallest negative number */
Void main ()
{
Int r [N], length, I, j;
Scanf ("% d", & length );
For (I = 0; I <length; I ++)
Scanf ("% d", & r [I]);
For (I = 0; I <length-1; I ++)
{
If (r [I]! = FLAG)
{
For (j = I + 1; j <length; j ++)
If (r [j] = r [I]) r [j] = FLAG;/* overwrites a duplicate value with a special mark */
}
}
For (I = 0; r [I]! = FLAG; I ++);/* Find the first special mark */
For (j = I + 1; j <length;)/* Delete the special mark in the sequence */
{
If (r [j]! = FLAG) r [I ++] = r [j ++];
Else j ++;
}
Length = I;/* modify the length of the sequence after the repeated values are deleted */
For (I = 0; I <length; I ++)
Printf ("%-4d", r [I]);
}

Delete repeated elements in an array from a two-dimensional array in C Language

You can use a one-dimensional array to calculate duplicate and non-repeated elements.
# Include <stdio. h>
Void main ()
{
Int I, j, k;
Int a [50];
Int B [50], c [50];
Int n, flag = 0;
For (I = 1; I <50; I ++) c [I] = 0;
Printf ("Please enter 50 data \ n ");
For (I = 0; I <50; I ++) scanf ("% d", & a [I]);
N = 0;
B [n] = a [0]; c [n] = 1; n ++;
For (I = 1; I <50; I ++ ){
For (k = 0; k <n; k ++ ){
If (a [I] = B [k]) {c [k] = c [k] + 1; flag = 1; break ;}
}
If (flag = 0) {B [n] = a [I]; c [n] = 1; n ++;} else {flag = 0 ;};
}
For (I = 0; I <50; I ++ ){
If (c [I] = 1) printf ("% d", B [I]);
}
Printf ("\ n =================\ n ");
For (I = 0; I <50; I ++ ){
If (c [I]> 1) printf ("% d -- % d \ n", B [I], c [I]);
}
}

--------------------
"Deleting repeated elements in an array" does not know what it means.
Array units are continuous allocation units. It is difficult to delete even dynamically allocated units.

Dynamic Allocation of units, you can use realloc to increase the allocation unit and reduce the allocation unit. However, it can only start from the end and the unit is continuous.

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