Sicily 1802 Atomic Nucleus Investigation(线段树)

新手赛的题目，让我回想起打酱油的时光

//线段树 #include<iostream> #include<cstdio> #include<cstring> #define INF 100000000 using namespace std; int T,M; char cmd[10],n; bool R[100005],G[100005]; struct seg { int l,r,_max,_min,delta;//记录最大值，最小值，最优差值，_max,_min为0表示不存在这个数 }tree[100005*4]; void update(int x)//回溯更新 { tree[x]._max = max(tree[2*x]._max,tree[2*x+1]._max); if(!tree[2*x]._min) tree[x]._min = tree[2*x+1]._min;//如果左子树不存在最小值，就用右子树的最小值 else tree[x]._min = tree[2*x]._min;//否则去左子树的最小值 tree[x].delta = min(tree[2*x].delta,tree[2*x+1].delta);//取最优子树的最小差值 if(tree[2*x]._max && tree[2*x+1]._min)//左子树的最大值和右子树的最小值存在的话 tree[x].delta = min(tree[x].delta,tree[2*x+1]._min - tree[2*x]._max); } void buildTree(int x,int l,int r) { tree[x].l = l; tree[x].r = r; tree[x]._max = 0; tree[x]._min = 0; tree[x].delta = INF; if(l == r) return; int mid = (l+r) >> 1; buildTree(2*x,l,mid); buildTree(2*x+1,mid+1,r); } void Insert(int x,int l,int r) { int mid = (tree[x].l + tree[x].r) >> 1; if(tree[x].l == l && tree[x].r == r) { tree[x]._max = tree[x]._min = l; return; } if(r <= mid) Insert(2*x,l,r); else if(l > mid) Insert(2*x+1,l,r); tree[x]._max = max(tree[2*x]._max,tree[2*x+1]._max); if(!tree[2*x]._min) tree[x]._min = tree[2*x+1]._min; else tree[x]._min = tree[2*x]._min; update(x); } void Remove(int x,int l,int r) { int mid = (tree[x].l + tree[x].r) >> 1; if(tree[x].l == l && tree[x].r == r) { tree[x]._max = tree[x]._min = 0; tree[x].delta = INF; return; } if(r <= mid) Remove(2*x,l,r); else if(l > mid) Remove(2*x+1,l,r); update(x); } int Query(int x)//直接询问根结点就能得出结果 { if(tree[x].delta == INF) return -1; else return tree[x].delta; } int main() { int x; bool first = 1; //freopen("in.txt","r",stdin); scanf("%d",&T); while(T--) { if(first) first = 0; else printf("/n"); buildTree(1,1,100000); memset(R,0,sizeof(R));//标记是否remove过 memset(G,0,sizeof(G));//标记是否generate过 scanf("%d",&M); while(M--) { scanf("%s",cmd); if(cmd[0] == 'g') { scanf("%d",&x); if(!G[x]) { G[x] = 1; Insert(1,x,x); R[x] = 0; } } if(cmd[0] == 'r') { scanf("%d",&x); if(!R[x]) { R[x] = 1; Remove(1,x,x); G[x] = 0; } } if(cmd[0] == 'q') printf("%d/n",Query(1)); } } }