【十二题解】 | #输入整型数组和排序标识，对其元素按照升序或降序进行排序#(归并排序)

好久没用过归并了，练一下

#include<stdio.h>

void merge(int* a, int *tmp, int l, int r, int rightend){

int lefend = r - 1;
int lenth = rightend - l + 1;
int loc = l;
while(l<=lefend && r <=rightend){
    if(a[l]<a[r]){
        tmp[loc++] = a[l++];
    }
    else{
        tmp[loc++] = a[r++];
    }
}
while(l<=lefend){
    tmp[loc++]=a[l++];
}
while(r<=rightend){
    tmp[loc++]=a[r++];
}
while(rightend >= 0){
    a[rightend--]=tmp[rightend];
}

}

void mort(int* a, int* tmp, int l, int rightend){

int center;
if(l < rightend){
    center = (rightend+l)/2;
    mort(a, tmp, l, center);
    mort(a, tmp, center+1, rightend);
    merge(a, tmp, l, center+1, rightend);
}

}

void mort_sort(int* a, int n){

int *tmp=(int*)malloc(sizeof(int)*n);
mort(a, tmp, 0, n-1);

}

int main(){

int number;
int data[1000]={0};
int sign;
while(scanf("%d", &number) != EOF){
    for(int i=0; i<number; i++){
        scanf("%d", &data[i]);
    }
    scanf("%d", &sign);
    mort_sort(data, number);
    if(sign){
        for(int i=number-1; i>=0; i--){
            printf("%d ", data[i]);
        }
    }
    else{
        for(int i=0; i<number; i++){
            printf("%d ", data[i]);
        }
    }
    printf("\n");
}

}