分治法--归并排序

归并排序，简单，直接见代码:

void merge_sort(int* A, int l, int r, int* T){if(r - l > 1){int m = (l+r) >> 1;merge_sort(A, l, m, T);merge_sort(A, m, r, T);int i = l, j = m, k = l;while(i < m && j < r){if(A[i] < A[j]){T[k++] = A[i++];}else{T[k++] = A[j++];}}while(i < m){T[k++] = A[i++];}while(j < r){T[k++] = A[j++];}//赋值回去for(i = l; i < r; i++){A[i] = T[i];}}}