1 #include <iostream>
2 #include <math.h>
3 #include <cstdio>
4 #define max(a,b) ((a)>(b)?(a):(b))
5 #define min(a,b) ((a)<(b)?(a):(b))
6
7 using namespace std;
8
9 const int maxn=50001;
10 int h[maxn];
11 int mx[maxn][16],mn[maxn][16];
12 int n,q;
13
14 void rmq_init()
15 {
16 int i,j;
17 for(j=1;j<=n;j++) mx[j][0]=mn[j][0]=h[j];
18 int m=floor(log((double)n)/log(2.0));
19 for(i=1;i<=m;i++){
20 for(j=n;j>0;j--){
21 mx[j][i]=mx[j][i-1];
22 if(j+(1<<(i-1))<=n) mx[j][i]=max(mx[j][i],mx[j+(1<<(i-1))][i-1]);
23 }
24 }
25 for(i=1;i<=m;i++){
26 for(j=n;j>0;j--){
27 mn[j][i]=mn[j][i-1];
28 if(j+(1<<(i-1))<=n) mn[j][i]=min(mn[j][i],mn[j+(1<<(i-1))][i-1]);
29 }
30 }
31 }
32
33 int rmq(int l,int r)
34 {
35 int m=floor(log((double)(r-l+1))/log(2.0));
36 int a=max(mx[l][m],mx[r-(1<<m)+1][m]);
37 int b=min(mn[l][m],mn[r-(1<<m)+1][m]);
38 return a-b;
39 }
40
41 int main()
42 {
43 freopen("input.txt","r",stdin);
44 int i,l,r;
45 int num;
46 scanf("%d",&num);
47 for(int jj=1;jj<=num;jj++){
48 scanf("%d%d",&n,&q);
49 for(i=1;i<=n;i++) scanf("%d",&h[i]);
50 rmq_init();
51 printf("Test case #%d:\n",jj);
52 for(i=0;i<q;i++){
53 scanf("%d%d",&l,&r);
54 printf("%d\n",rmq(l,r));
55 }
56
57 }
58 return 0;
59 }
60 用这个了
61 思路比较清晰 速度也不慢
1 template < class Type>
2 class rmq_st{
3 private:
4 Type* body;
5 int** mi;
6 int size;
7 int len;
8
9 int dint(double a){
10 int buf=a;
11 if(buf>a){
12 --buf;
13 }
14 return buf;
15 }
16
17 int mlen(int l,int r){
18 double buf=log((double)(r-l+1))/log((double)2);
19 return dint(buf)
20 }
21 bool (*less)(Type& t1,Type& t2);
22
23 public:
24
25
26 //构造函数 : (待求数组,大小,小于函数)
27 rmq_st(Type* con,int s,bool (*lessthan)(Type& t1,Type& t2));
28
29 ~rmq_st();//解构
30
31 Type get_body(int p);//返回指定索引的元素
32
33 int query_index(int l,int r);//返回指定区间最小值的元素索引
34
35 Type query(int l,int r);//返回指定区间的最小元素
36 };
37
38 template < class Type>
39 rmq_st< Type>::rmq_st(Type* con,int s,bool (*lessthan)(Type& t1,Type& t2)){
40 less=lessthan;
41 body=con;
42 size=s;
43 len=mlen(0,s-1)+1;
44 mi=new int*[size];
45 int i,j;
46 for(i=0;i< size;++i){
47 mi[i]=new int[len];
48 }
49 int bound;
50 int a,b;
51 for(i=0;i< size;++i){
52 mi[i][0]=i;
53 }
54 for(i=1;i< len;++i){
55 bound=n-(1<< i)+1;
56 for(j=0;j< bound;++j){
57 a=mi[j][i-1];
58 b=mi[j+(1<< (i-1))][i-1];
59 mi[j][i]=less(body[a],body[b])?a:b;
60 }
61 }
62 }
63
64 template < class Type>
65 rmq_st< Type>::~rmq_st(){
66 int i;
67 for(i=0;i< size;++i){
68 delete[] mi[i];
69 }
70 delete[] mi;
71 }
72
73 template < class Type>
74 Type rmq_st< Type>::get_body(int p){
75 return body[p];
76 }
77
78 template < class Type>
79 int rmq_st< Type>::query_index(int l,int r){
80 int length=mlen(l,r);
81 int a=mi[l][length];
82 int b=mi[r-(1<< length)+1][length];
83 return less(body[a],body[b])?a:b;
84 }
85
86 template < class Type>
87 Type rmq_st< Type>::query(int l,int r){
88 int length=mlen(l,r);
89 int a=mi[l][length];
90 int b=mi[r-(1<< length)+1][length];
91 return less(body[a],body[b])?body[a]:body[b];
92 }
93
94 /*----------------Example : POJ 3264 Memory:7708K Time:3230MS-----------------*/
95
96 int cow[50001];
97 int n,q;
98
99 bool cmpmin(int& t1,int& t2){
100 return t1< t2;
101 }
102
103 bool cmpmax(int& t1,int& t2){
104 return t1>t2;
105 }
106
107 int main()
108 {
109 // freopen("1.in","r",stdin);
110 scanf("%d %d",&n,&q);
111 int i;
112 for(i=0;i< n;++i){
113 scanf("%d",&cow[i]);
114 }
115 rmq_st< int> minst(cow,n,cmpmin);
116 rmq_st< int> maxst(cow,n,cmpmax);
117 int a,b;
118 for(i=0;i< q;++i){
119 scanf("%d %d",&a,&b);
120 --a;
121 --b;
122 printf("%d\n",maxst.query(a,b)-minst.query(a,b));
123 }
124 return 0;
125 }
342ms.................
