HDU-DuoXiao第二场hdu 6315 Naive Operations 线段树
题意:
对于一个数列a,初始为0,每个a[ i ]对应一个b[i],只有在这个数字上加了b[i]次后,a[i]才会+1。
有q次操作,一种是个区间加1,一种是查询a的区间和。
思路:
线段树,一开始没用lazy,TLE了,然后开始想lazy的标记,这棵线段树的特点是,每个节点维护 :一个区间某个a 要增加1所需个数的最小值,一个区间已加上的mx的最大值标记,还有就是区间和sum。 (自己一开始没有想到mx标记,一度想把lazy传回去。
(思路差一点就多开节点标记。
#include <iostream> #include <cstdio> #include <algorithm> #include <cstring> #include <string> #include <vector> #include <map> #include <set> #include <queue> #include <list> #include <cstdlib> #include <iterator> #include <cmath> #include <iomanip> #include <bitset> #include <cctype> #include <stack> #pragma comment(linker, "/STACK:102400000,102400000") //c++ using namespace std; #define lson (l , mid , rt << 1) #define rson (mid + 1 , r , rt << 1 | 1) #define debug(x) cerr << #x << " = " << x << "\n"; #define pb push_back #define pq priority_queue typedef long long ll; typedef unsigned long long ull; typedef pair<ll ,ll > pll; typedef pair<int ,int > pii; #define fi first #define se second #define OKC ios::sync_with_stdio(false);cin.tie(0);cout.tie(0) #define FT(A,B,C) for(int A=B;A <= C;++A) //用来压行 #define REP(i , j , k) for(int i = j ; i < k ; ++i) const ll mos = 0x7FFFFFFF; //2147483647 const ll nmos = 0x80000000; //-2147483648 const int inf = 0x3f3f3f3f; template<typename T> inline T read(T&x){ x=0;int f=0;char ch=getchar(); while (ch<'0'||ch>'9') f|=(ch=='-'),ch=getchar(); while (ch>='0'&&ch<='9') x=x*10+ch-'0',ch=getchar(); return x=f?-x:x; } // #define _DEBUG; //*// #ifdef _DEBUG freopen("input", "r", stdin); // freopen("output.txt", "w", stdout); #endif /*----------------------show time----------------------*/ int n,q; const int maxn = 100009; int a[maxn],b[maxn]; int sum[maxn*4]; int lazy[maxn*4]; int mx[maxn*4]; int nd[maxn*4]; void pushup(int rt){ sum[rt] = sum[rt<<1] + sum[rt<<1|1]; nd[rt] = min(nd[rt<<1] , nd[rt<<1|1]); mx[rt] = max(mx[rt<<1], mx[rt<<1|1]); // lazy[rt] = lazy[rt<<1] + lazy[rt<<1|1]; // lazy[rt<<1] = lazy[rt<<1|1] = 0; } void pushdown(int rt){ if(lazy[rt]){ lazy[rt<<1]+= lazy[rt]; lazy[rt<<1|1] += lazy[rt]; mx[rt<<1] +=lazy[rt]; mx[rt<<1|1] +=lazy[rt]; lazy[rt] = 0; } } void build(int l,int r,int rt){ if(l==r){ nd[rt] = b[l]; lazy[rt] = mx[rt] = sum[rt] = 0; return; } int mid = (l+r)/2; build(l,mid,rt<<1); build(mid+1,r,rt<<1|1); pushup(rt); } void update(int l,int r,int rt,int L,int R,int k){ if(l>=L && r<=R) { mx[rt] ++; if(mx[rt] < nd[rt]){ lazy[rt]++; return; } if(l==r){ sum[rt]++; nd[rt]+=b[l]; lazy[rt] = 0; return; } } int mid = (l+r)/2; pushdown(rt); if(mid >= L)update(l,mid,rt<<1,L,R,k); if(mid<R)update(mid+1,r,rt<<1|1,L,R,k); pushup(rt); } ll query(int l,int r,int rt,int L,int R){ if(l>=L&&r<=R){ return sum[rt]; } int mid = (l+r)/2; // pushdown(rt); ll ans = 0; if(mid >= L)ans += query(l,mid,rt<<1,L,R); if(mid < R)ans += query(mid+1,r,rt<<1|1,L,R); return ans; } int main(){ while(~scanf("%d%d", &n, &q)){ for(int i=1; i<=n; i++){ scanf("%d", &b[i]); } char s[20]; build(1,n,1); for(int i=1; i<=q; i++){ int l,r; scanf("%s%d%d", s, &l, &r); if(s[0]=='a'){ update(1,n,1,l,r,0); // debug(a[5]); } else { ll ans = query(1,n,1,l,r); printf("%lld\n",ans); } } } return 0; }
skr