线段树
http://acm.hdu.edu.cn/showproblem.php?pid=4302
1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<algorithm> 5 #include<ctime> 6 7 using namespace std; 8 9 typedef long long ll; 10 const int maxn = 100100; 11 const int inf = (-1u)>>2; 12 int L, n; 13 struct Node 14 { 15 int max_, min_; 16 int num; 17 }node[maxn * 4]; 18 #define lc (pos << 1) 19 #define rc (pos << 1 | 1) 20 21 void build(int pos, int l,int r) 22 { 23 if(l > r) return; 24 25 node[pos].num = 0; 26 node[pos].min_ = inf; 27 node[pos].max_ = -inf; 28 29 if(r == l) return; 30 31 32 int mid = (l + r) >> 1; 33 build(lc, l, mid); 34 build(rc, mid + 1, r); 35 } 36 37 void insert(int pos, int l,int r,int p, int dx)//在l到r中插入p 38 { 39 if(l > r || p < l || p > r) return; 40 if(l == r) 41 { 42 node[pos].num += dx; 43 if(node[pos].num) 44 node[pos].max_ = node[pos].min_ = p; 45 else 46 { 47 node[pos].min_ = inf; 48 node[pos].max_ = -inf; 49 } 50 return; 51 } 52 53 int mid = (l + r) >> 1; 54 insert(lc, l, mid, p, dx); 55 insert(rc, mid + 1, r, p, dx); 56 57 node[pos].max_ = max(node[lc].max_, node[rc].max_); 58 node[pos].min_ = min(node[lc].min_, node[rc].min_); 59 } 60 61 int search_max(int pos, int l,int r,int x, int y)//在x到y这一段找最大值 62 { 63 if(y < l || x > r || l > r || x > y) return -inf; 64 if(x <= l && r <= y) return node[pos].max_; 65 66 int mid = (l + r) >> 1; 67 68 return max(search_max(lc, l, mid, x, y), search_max(rc, mid + 1, r, x, y)); 69 } 70 71 int search_min(int pos, int l,int r,int x, int y) 72 { 73 if(y < l || x > r || l > r || x > y) return inf; 74 if(x <= l && r <= y) return node[pos].min_; 75 76 int mid = (l + r) >> 1; 77 78 return min(search_min(lc, l, mid, x, y), search_min(rc, mid + 1, r, x, y)); 79 } 80 81 int main() 82 { 83 int T; 84 scanf("%d", &T); 85 for(int cas = 1; cas <= T; cas++) 86 { 87 scanf("%d%d", &L, &n); 88 build(1, 0, L); 89 ll ans = 0; 90 scanf(" "); 91 int now = 0, dir = 1; 92 for(int i = 0; i < n; i++) 93 { 94 int flag, x; 95 char s[100]; 96 gets(s); 97 sscanf(s, "%d%d", &flag, &x); 98 if(flag) 99 { 100 int l = search_max(1, 0, L, 0, now), r = search_min(1, 0, L, now, L); 101 102 if(l <= -inf && r >= inf) 103 continue; 104 else 105 if(l <= -inf) 106 ans += r - now, now = r, dir = 1; 107 else 108 if(r >= inf) 109 ans += now - l, now = l, dir = 0; 110 else 111 if(now - l < r - now) 112 ans += now - l, now = l, dir = 0; 113 else 114 if(now - l > r - now) 115 ans += r - now, now = r, dir = 1; 116 else 117 if(dir) 118 ans += r - now, now = r, dir = 1; 119 else 120 ans += now - l, now = l, dir = 0; 121 122 insert(1, 0, L, now, -1); 123 } 124 else 125 insert(1, 0, L, x, 1); 126 } 127 128 printf("Case %d: %lld\n", cas, ans); 129 } 130 131 //printf("time=%d\n", clock() - begin); 132 return 0; 133 }
