HDU 4614 线段树+二分
一开始做用自己的方法，一直WA，自己也出不出错误的例子，放弃了自己的代码，看了一下别人的方法都是线段树+二分，逻辑很清晰，也很好写，基本就是板子。
#include
#include
#include
#include
using namespace std;
struct node
{
int sum,lz;
}a[50005 << 3];
void build(int d, int l, int r)
{
a[d].sum = r - l + 1; a[d].lz = -1;
if(l == r) return;
int m = (l+r) >> 1;
build(d*2,l,m); build(d*2+1,m+1,r);
}
void pushup(int d)
{
a[d].sum = a[d*2].sum + a[d*2 + 1].sum;
}
void pushdown(int d, int l, int r)
{
if(a[d].lz != -1)
{
int m = (l+r) >> 1;
int ld = d*2, rd = ld + 1;
a[ld].lz = a[rd].lz = a[d].lz;
a[ld].sum = (m - l + 1)*a[d].lz;
a[rd].sum = (r - m)*a[d].lz;
a[d].lz = -1;
}
}
int query(int d, int l, int r, int ql, int qr)
{
if(ql <= l && r <= qr)
{
return a[d].sum;
}
int m = (l+r) >> 1;
int ans = 0;
pushdown(d,l,r);
if(ql <= m) ans += query(d*2,l,m,ql,qr);
if(m < qr) ans += query(d*2+1,m+1,r,ql,qr);
return ans;
}
int query_0(int d, int l, int r, int ql, int qr)
{
if(ql <= l && r <= qr)
{
return r - l +1 - a[d].sum;
}
int m = (l+r) >> 1; int ans = 0;
pushdown(d,l,r);
if(ql <= m) ans += query_0(d*2,l,m,ql,qr);
if(m < qr) ans += query_0(d*2+1,m+1,r,ql,qr);
return ans;
}
void update(int d, int l, int r, int ql, int qr, int c)
{
if(ql <= l && r <= qr)
{
a[d].lz = c;
a[d].sum = (r - l + 1)*c;
return;
}
pushdown(d,l,r);
int m = (l +r) >> 1;
if(ql <= m) update(d*2,l,m,ql,qr,c);
if(m < qr)update(d*2+1,m+1,r,ql,qr,c);
pushup(d);
return;
}
int main()
{
int n,m;
int times; cin >> times;
while(times --)
{
scanf("%d%d",&n,&m);
build(1,1,n);
while(m -- )
{
int k,x,y;
scanf("%d%d%d",&k,&x,&y);
if(k == 1)
{
int t = query(1,1,n,x+1,n);
if(t == 0)
{
printf("Can not put any one.\n");
continue;
}
int lsum = 0;
if(x != 0)
lsum = query(1,1,n,1,x);
lsum ++;
//cout <<" ff " <> 1;
nows = query(1,1,n,l,m);
//cout << l << " " <= lsum) r = m;
else if(nows < lsum)
{
lsum -= nows;
l = m + 1;
}
}
lp = l;
int rsum = min(y,t); l = lp,r = n;
while(l < r)
{
m = (l+r) >> 1;
nows = query(1,1,n,l,m);
// cout << l <<" " <= rsum) r = m;
else if(nows < rsum)
{
rsum -= nows;
l = m + 1;
}
}
int rp = l;
printf("%d %d\n",lp- 1,rp-1);
update(1,1,n,lp,rp,0);
}
else
{
printf("%d\n",query_0(1,1,n,x+1,y+1));
update(1,1,n,x+1,y+1,1);
}
}
printf("\n");
}
} ——————————————————————————————————————————————————分割线
顺便贴一下WA的代码，没有找出来哪里错了
#include
#include
#include
#include
#pragma comment(linker, "/STACK:36777216")
using namespace std;
struct node
{
int sum,st,en;
int lz;
}a[50010<<4];
void build(int d,int l, int r)
{
int len = r - l + 1;
a[d].sum = len; a[d].st = l,a[d].en = r;
a[d].lz = -1;
if(l == r) return;
int m = (l+r)>>1;
build(d*2,l,m);
build(d*2+1,m+1,r);
return;
}
void pushup(int d)
{
int ld = d*2,rd = d*2 +1;
a[d].sum = a[ld].sum + a[rd].sum;
if(a[d].sum == 0) return;
if(a[ld].sum != 0) a[d].st = a[ld].st;
else a[d].st = a[rd].st;
if(a[rd].sum != 0) a[d].en = a[rd].en;
else a[d].en = a[ld].en;
return ;
}
void push1(int d, int l, int r)
{
if(a[d].sum == r - l +1 && a[d].lz == 0)
{
int ld = 2*d, rd = 2*d + 1;
int m = (l+r)>>1;
a[ld].sum = m - l +1; a[rd].sum = r - m;
a[ld].st = l, a[ld].en = m;
a[rd].st = m+1, a[rd].en = r;
a[d].lz = -1;
a[ld].lz = 0, a[rd].lz = 0;
}
return;
}
int al,ar,s,ts;
void pushdown(int d , int l, int r)
{
//cout << l << " pp " <> 1;int ld = d*2, rd = ld + 1;
if(a[ld].sum && s)pushdown(ld,l,m);
if(a[rd].sum && s)pushdown(rd,m+1,r);
pushup(d);
}
}
void push0(int d, int l, int r)
{
if(a[d].sum == 0 && a[d].lz == 1)
{
a[d].lz = -1;
int ld = 2*d, rd = 2*d + 1;
int m = (l+r)>>1;
a[ld].sum = 0; a[rd].sum = 0;
a[ld].lz = 1; a[rd].lz = 1;
}
}
void query(int d, int l, int r, int t)
{
if(l == t)
{
//cout << l <<" "<< r <<" "< s)
{
if(s == ts) al = a[d].st;
pushdown(d,l,r);
}
else if(a[d].sum <= s)
{
if(s== ts) al = a[d].st;
s -= a[d].sum; ar = a[d].en; a[d].lz = 1;
a[d].sum = 0;
}
return ;
}
push1(d,l,r);
int m = (l+r) >>1;
//cout << l << " " << r <<" " << a[d].sum <<" "< 0 && a[d*2+1].sum) query(d*2+1,m+1,r,max(t,m+1));
pushup(d);
}
int update(int d, int l, int r ,int ql, int qr)
{
int ans = 0;
if(ql <= l && r <= qr)
{
ans =r - l+ 1 - a[d].sum;
//cout << l <<" gg " <>1;
if(ql <= m) ans += update(d*2,l,m,ql,qr);
if(m < qr) ans += update(d*2+1,m+1,r,ql,qr);
pushup(d);
return ans;
}
int main()
{
int times,n,m,op;
scanf("%d",×);
while(times --)
{
int x,y;
scanf("%d%d",&n,&m);
build(1,1,n);
while(m --)
{
scanf("%d%d%d",&op,&x,&y);
if(op == 1)
{
s = y;ts = y; x += 1;
// cout << n <<" "<< x<< endl;
query(1,1,n,x);
if(s < y)
printf("%d %d\n",al -1,ar - 1);
else
printf("Can not put any one.\n");
}
else
{
printf("%d\n",update(1,1,n,x+1,y+1));
}
}
printf("\n");
}
}