九度oj 1407 快速找出最小数

原题链接：http://ac.jobdu.com/problem.php?pid=1407 
线段树，区间更新，查询区间最小值。 

注意区间更新,查询的时候，区间$\begin{align*}[L,R] \end{align*}$$\begin{align*}L \end{align*}$都可能大于$\begin{align*}R\end{align*}$。。

有个地方写sb了害的我wa了好几次%>_<%。

 1 #include<algorithm>

 2 #include<iostream>

 3 #include<cstdlib>

 4 #include<cstring>

 5 #include<cstdio>

 6 #define lc root<<1

 7 #define rc root<<1|1

 8 #define mid ((l+r)>>1)

 9 using std::min;

10 const int Max_N = 100010;

11 const int INF = ~0u >> 1;

12 struct Node {

13     int val, add;

14 };

15 struct SegTree {

16     Node seg[Max_N << 2];

17     inline void push_up(int root) {

18         seg[root].val = min(seg[lc].val, seg[rc].val);

19     }

20     inline void built(int root, int l, int r) {

21         seg[root].add = 0;

22         if (l == r) {

23             scanf("%d", &seg[root].val);

24             return;

25         }

26         built(lc, l, mid);

27         built(rc, mid + 1, r);

28         push_up(root);

29     }

30     inline void push_down(int root) {

31         if (seg[root].add != 0) {

32             int &_add = seg[root].add;

33             seg[lc].add += _add;

34             seg[lc].val += _add;

35             seg[rc].add += _add;

36             seg[rc].val += _add;

37             _add = 0;

38         }

39     }

40     inline void update(int root, int l, int r, int x, int y, int v) {

41         if (x > r || y < l) return;

42         if (x <= l && y >= r) {

43             seg[root].add += v;

44             seg[root].val += v;

45             return;

46         }

47         push_down(root);

48         update(lc, l, mid, x, y, v);

49         update(rc, mid + 1, r, x, y, v);

50         push_up(root);

51     }

52     inline int query(int root, int l, int r, int x, int y) {

53         if (x > r || y < l) return INF;

54         if (x <= l && y >= r) return seg[root].val;

55         push_down(root);

56         int v1 = query(lc, l, mid, x, y);

57         int v2 = query(rc, mid + 1, r, x, y);

58         return min(v1, v2);

59     }

60 }seg;

61 int main() {

62 #ifdef LOCAL

63     freopen("in.txt", "r", stdin);

64     freopen("out.txt", "w+", stdout);

65 #endif

66     char buf[100];

67     int n, m, a, b, c;

68     while (~scanf("%d", &n)) {

69         seg.built(1, 1, n);

70         scanf("%d\n", &m);

71         while (m--) {

72             gets(buf);

73             char *p = strchr(buf, ' ');

74             if (strchr(++p, ' ')) {

75                 sscanf(buf, "%d %d %d", &a, &b, &c);

76                 if (a <= b) {

77                     seg.update(1, 1, n, ++a, ++b, c);

78                 } else {

79                     seg.update(1, 1, n, ++a, n, c);

80                     seg.update(1, 1, n, 1, ++b, c);

81                 }

82             } else {

83                 sscanf(buf, "%d %d", &a, &b);

84                 if (a <= b) {

85                     printf("%d\n", seg.query(1, 1, n, ++a, ++b));

86                 } else {

87                     int v1 = seg.query(1, 1, n, ++a, n);

88                     int v2 = seg.query(1, 1, n, 1, ++b);

89                     printf("%d\n", min(v1, v2));

90                 }

91             }

92         }

93     }

94     return 0;

95 }

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