Lung-Yu,Tsai 的部落格

題目:

Given an array and a value, remove all instances of that value in-place and return the new length.

Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.

The order of elements can be changed. It doesn't matter what you leave beyond the new length.

Example:

Given nums = [3,2,2,3], val = 3,

Your function should return length = 2, with the first two elements of nums being 2.

思路:

移除陣列中含有指定的數值(val).

其中比較困難的部分是要在原本的陣列中移動元素.

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#define MIN(a,b) (((a)<(b))?(a):(b))

int removeElement(int* nums, int numsSize, int val) {
    int i = 0,j;
    int count = 0;
    int idx = 0;
    int end = numsSize;
    for(i=0 ; i< end; i++){
    	if(nums[i]==val){
            for(j=i;j<(end-1);j++){
                nums[j]=nums[j+1];
            }  
            end--;
            i--;
        }else{
            count++;
        } 
    }
    
    return count;
}