题目链接:http://www.lydsy.com/JudgeOnline/problem.php?id=1858
需要维护连续的0、连续的1、3种lazy和一个和
让我调到半夜的一个地方:修改时一定要先pushdown!!!
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 |
#include<bits/stdc++.h> #define MAXN 100010 using namespace std; inline int rd(){ int x=0,y=1;char c=getchar(); while(c<'0' || c>'9'){if(c=='-')y=-y;c=getchar();} while(c>='0'&&c<='9')x=x*10+c-'0',c=getchar(); return x*y; } struct node{ int l,r,len; int lazy,sum; int ml1,mr1,mm1; int ml0,mr0,mm0; }tree[MAXN*6]; int n,m; inline void pushup(int x){ int l=x*2,r=x*2+1; tree[x].sum=tree[l].sum+tree[r].sum; tree[x].mm1=tree[l].mr1+tree[r].ml1; tree[x].mm0=tree[l].mr0+tree[r].ml0; if(tree[l].ml1==tree[l].len)tree[x].ml1=tree[l].ml1+tree[r].ml1; else tree[x].ml1=tree[l].ml1; if(tree[l].ml0==tree[l].len)tree[x].ml0=tree[l].ml0+tree[r].ml0; else tree[x].ml0=tree[l].ml0; if(tree[r].mr1==tree[r].len)tree[x].mr1=tree[r].mr1+tree[l].mr1; else tree[x].mr1=tree[r].mr1; if(tree[r].mr0==tree[r].len)tree[x].mr0=tree[r].mr0+tree[l].mr0; else tree[x].mr0=tree[r].mr0; tree[x].mm1=max(tree[x].mm1,max(tree[l].mm1,tree[r].mm1)); tree[x].mm0=max(tree[x].mm0,max(tree[l].mm0,tree[r].mm0)); } void build(int x,int l,int r){ tree[x].l=l; tree[x].r=r; tree[x].len=r-l+1; if(l==r){ tree[x].sum=tree[x].ml1=tree[x].mr1=tree[x].mm1=rd(); tree[x].ml0=tree[x].mr0=tree[x].mm0=tree[x].sum^1; return; } int mid=(l+r)/2; build(x*2,l,mid); build(x*2+1,mid+1,r); pushup(x); } inline void Rev(int x){ swap(tree[x].ml1,tree[x].ml0); swap(tree[x].mr1,tree[x].mr0); swap(tree[x].mm1,tree[x].mm0); } inline void pushdown(int x){ int l=x*2,r=x*2+1; if(tree[x].lazy==1){ tree[l].lazy=tree[r].lazy=1; tree[l].sum=0; tree[r].sum=0; tree[l].ml1=tree[l].mr1=tree[l].mm1=0; tree[r].ml1=tree[r].mr1=tree[r].mm1=0; tree[l].ml0=tree[l].mr0=tree[l].mm0=tree[l].len; tree[r].ml0=tree[r].mr0=tree[r].mm0=tree[r].len; } if(tree[x].lazy==2){ tree[l].lazy=tree[r].lazy=2; tree[l].sum=tree[l].len; tree[r].sum=tree[r].len; tree[l].ml1=tree[l].mr1=tree[l].mm1=tree[l].len; tree[r].ml1=tree[r].mr1=tree[r].mm1=tree[r].len; tree[l].ml0=tree[l].mr0=tree[l].mm0=0; tree[r].ml0=tree[r].mr0=tree[r].mm0=0; } if(tree[x].lazy==3){ if(tree[l].lazy==1)tree[l].lazy=2; else if(tree[l].lazy==2)tree[l].lazy=1; else if(tree[l].lazy==3)tree[l].lazy=0; else tree[l].lazy=3; if(tree[r].lazy==1)tree[r].lazy=2; else if(tree[r].lazy==2)tree[r].lazy=1; else if(tree[r].lazy==3)tree[r].lazy=0; else tree[r].lazy=3; tree[l].sum=tree[l].len-tree[l].sum; tree[r].sum=tree[r].len-tree[r].sum; Rev(l);Rev(r); } tree[x].lazy=0; } void modify(int x,int l,int r,int k){ pushdown(x); if(tree[x].l==l && tree[x].r==r){ tree[x].lazy=k; if(k==1){ tree[x].sum=0; tree[x].ml1=tree[x].mr1=tree[x].mm1=0; tree[x].ml0=tree[x].mr0=tree[x].mm0=tree[x].len; } if(k==2){ tree[x].sum=tree[x].len; tree[x].ml1=tree[x].mr1=tree[x].mm1=tree[x].len; tree[x].ml0=tree[x].mr0=tree[x].mm0=0; } if(k==3){ tree[x].sum=tree[x].len-tree[x].sum; Rev(x); } return; } int mid=(tree[x].l+tree[x].r)/2; if(r<=mid)modify(x*2,l,r,k); else if(l>mid)modify(x*2+1,l,r,k); else modify(x*2,l,mid,k),modify(x*2+1,mid+1,r,k); pushup(x); } int query1(int x,int l,int r){ if(tree[x].l==l && tree[x].r==r)return tree[x].sum; pushdown(x); int mid=(tree[x].l+tree[x].r)/2; if(r<=mid)return query1(x*2,l,r); else if(l>mid)return query1(x*2+1,l,r); else return query1(x*2,l,mid)+query1(x*2+1,mid+1,r); } inline int queryl(int x,int l,int r){ if(tree[x].ml1+l>r)return r-l+1; return tree[x].ml1; } inline int queryr(int x,int l,int r){ if(tree[x].mr1+l>r)return r-l+1; return tree[x].mr1; } int query2(int x,int l,int r){ if(tree[x].l==l && tree[x].r==r)return max(tree[x].mm1,max(tree[x].ml1,tree[x].mr1)); pushdown(x); int mid=(tree[x].l+tree[x].r)/2; if(r<=mid)return query2(x*2,l,r); else if(l>mid)return query2(x*2+1,l,r); else return max(max(query2(x*2,l,mid),query2(x*2+1,mid+1,r)),queryr(x*2,l,mid)+queryl(x*2+1,mid+1,r)); } int main(){ n=rd(),m=rd(); build(1,1,n); int op,x,y; while(m--){ op=rd(),x=rd()+1,y=rd()+1; if(op<3)modify(1,x,y,op+1); if(op==3)printf("%d\n",query1(1,x,y)); if(op==4)printf("%d\n",query2(1,x,y)); } return 0; } |