CF438D The Child and Sequence(線段樹區間取模)
阿新 • • 發佈:2021-08-01
思路
維護區間的最大值,取模的時候如果最大值小於模數就跳過此區間;否則,對每個點暴力修改。由於每次取模後 \(x \bmod p<2/x\),所以每個點最多被修改\(logx\)次。
程式碼
// Problem: D. The Child and Sequence // Contest: Codeforces - Codeforces Round #250 (Div. 1) // URL: https://codeforces.com/problemset/problem/438/D // Memory Limit: 256 MB // Time Limit: 4000 ms // // Powered by CP Editor (https://cpeditor.org) #include<bits/stdc++.h> using namespace std; typedef long long ll; typedef unsigned long long ull; typedef pair<ll, ll>PLL; typedef pair<int, int>PII; typedef pair<double, double>PDD; #define I_int ll inline ll read() { ll x = 0, f = 1; char ch = getchar(); while(ch < '0' || ch > '9') { if(ch == '-')f = -1; ch = getchar(); } while(ch >= '0' && ch <= '9') { x = x * 10 + ch - '0'; ch = getchar(); } return x * f; } inline void out(ll x){ if (x < 0) x = ~x + 1, putchar('-'); if (x > 9) out(x / 10); putchar(x % 10 + '0'); } inline void write(ll x){ if (x < 0) x = ~x + 1, putchar('-'); if (x > 9) write(x / 10); putchar(x % 10 + '0'); } #define read read() #define closeSync ios::sync_with_stdio(0);cin.tie(0);cout.tie(0) #define multiCase int T;cin>>T;for(int t=1;t<=T;t++) #define rep(i,a,b) for(int i=(a);i<=(b);i++) #define repp(i,a,b) for(int i=(a);i<(b);i++) #define per(i,a,b) for(int i=(a);i>=(b);i--) #define perr(i,a,b) for(int i=(a);i>(b);i--) ll ksm(ll a, ll b) { ll res = 1; while(b) { if(b & 1)res = res * a ; a = a * a ; b >>= 1; } return res; } const int inf = 0x3f3f3f3f; const int maxn=1e5+7,maxm=210000; int n,m,a[maxn]; struct node{ int l,r; ll sum,maxx; }tr[maxn<<2]; void pushup(int u){ tr[u].sum=tr[u<<1].sum+tr[u<<1|1].sum; tr[u].maxx=max(tr[u<<1].maxx,tr[u<<1|1].maxx); } void build(int u,int l,int r){ tr[u]={l,r}; if(l==r){ tr[u].sum=tr[u].maxx=a[l]; return ; } int mid=(l+r)/2; build(u<<1,l,mid);build(u<<1|1,mid+1,r); pushup(u); } ll query_sum(int u,int l,int r){ if(tr[u].l>=l&&tr[u].r<=r) return tr[u].sum; int mid=(tr[u].l+tr[u].r)/2; ll res=0; if(l<=mid) res+=query_sum(u<<1,l,r); if(r>mid) res+=query_sum(u<<1|1,l,r); return res; } void update_mod(int u,int l,int r,ll x){ if(tr[u].l>=l&&tr[u].r<=r&&tr[u].maxx<x) return ; if(tr[u].l>=l&&tr[u].r<=r&&tr[u].l==tr[u].r){ tr[u].maxx%=x;tr[u].sum%=x; return ; } int mid=(tr[u].l+tr[u].r)/2; if(l<=mid) update_mod(u<<1,l,r,x); if(r>mid) update_mod(u<<1|1,l,r,x); pushup(u); } void update_pos(int u,int l,int r,int x){ if(tr[u].l==l&&tr[u].r==r){ tr[u].sum=tr[u].maxx=x; return ; } int mid=(tr[u].l+tr[u].r)/2; if(l<=mid) update_pos(u<<1,l,r,x); if(r>mid) update_pos(u<<1|1,l,r,x); pushup(u); } int main(){ n=read,m=read; rep(i,1,n) a[i]=read; build(1,1,n); while(m--){ int op=read; if(op==1){ int l=read,r=read; printf("%lld\n",query_sum(1,l,r)); } else if(op==2){ int l=read,r=read; ll x=read; update_mod(1,l,r,x); } else{ int k=read,x=read; update_pos(1,k,k,x); } } return 0; }