算法

1.快排排序
void quick_sort(int q[],int l,int r)
{
if(l>=r)return ;
int i=l-1,j=r+1;
int x=q[l+r>>1];
while(i<j){
do i++;while(q[i]<x);
do j--;while(q[j]>x);
if(i<j)swap(q[i],q[j];
}
quick_sort(q,l,j);
quick_sort(q,j+1,r);
}
2.归并排序
void merge_sort(int q[],int l,int r)
{
if(l>=r)return;
int mid=l=r>>1;
merge_sort(q,l,mid),merge_sort(q,mid+1,r);
int k=0,i=l,j=mid+1;
while(i<=mid&&j<=r)
{
if(q[i]<=q[j])temp[k++]=q[i++];
else tmp[k++]=q[j++];
}
while(i<=mid)tmp[k++]=q[i++];
while(j<=r)tmp[k++]=q[j++];
for(i=l,j=0;i<=r;i++,j++)q[i]=tmp[j];
}
3.二分算法（整数）
bool check(int x).....//x满足某种性质
void bsearch_1(int l,int r)
{
while(i<j)
{
int mid=l+r+1>>1;
if(check(mid))l=mid;
r=mid-1;
}
return l;
}
void bsearch_2(int l,int r)
{
while(i<j)
{
int mid=l+r>>1;
if(check(mid))r=mid;
r=mid+1;
}
return l;
}