在大输入时释放对象的校验和错误

我写了一个程序，计算。txt文件中的反转数(第一个数字-数字的数量，而不是数字本身)。对于小输入(5或10个数字)，它工作得很好，但是当输入100,000个数字(并且每个数字都小于100,000)时，我得到以下错误:

incorrect checksum for freed object - object was probably modified after being freed.
*** set a breakpoint in malloc_error_break to debug***

代码如下:

#include <stdio.h>
long int merge(int *arr, const int start, const int half, const int end)
{
        int s=start;
        int i=0;
        int cinv=0;
        int j=half+1;
        int* barr = new int[end+start-1];
        while((s<=half)&&(j<=end)){
                if(arr[s]<=arr[j]){
                        barr[i]=arr[s];
                        s++;
                }
                else{
                        barr[i]=arr[j];
                        j++;
                        cinv++;
                }
                i++;
        }
        if(s>half){
                for(int k = j;k<=end;k++){
                        barr[i]=arr[k];
                        i++;
                }
        }
        else{
                for(int k=s;k<=half;k++){
                        barr[i]=arr[k];
                        i++;
                }
        }
        for(int k=0;k<=end-start;k++) {
                arr[k+start]=barr[k];
        }
        delete[] barr;
        return cinv;
}
long int mergesort(int* arr, int start, int end){
    int half=(start+end)/2;
    long int cinv=0;
    if (start<end){
        cinv+=mergesort(arr, start, half);
        cinv+=mergesort(arr, half+1, end);
        cinv+=merge(arr, start, half, end);
        return cinv;
    }
    return cinv;
}
int main(){
    int len;
    freopen("input.txt", "rt", stdin);
    freopen("output.txt", "wt", stdout);
    scanf("%d", &len);
    int *arr= new int[len];
    for (int i=0; i<len; i++){
        scanf("%d", &arr[i]);
    }
    long int cinv=mergesort(arr, 0, len-1);
    printf("nInversions with merge=%ld", cinv);
    delete [] arr;
    return 0;
}

提前感谢您的帮助。