The Water Problem
Time Limit: 1500/1000 MS (Java/Others) Memory Limit: 131072/131072 K (Java/Others)
Total Submission(s): 602 Accepted Submission(s): 485
Problem Description
In
Land waterless, water is a very limited resource. People always fight
for the biggest source of water. Given a sequence of water sources with a1,a2,a3,...,an representing the size of the water source. Given a set of queries each containing 2 integers l and r, please find out the biggest water source between al and ar.
Input
First you are given an integer T indicating the number of test cases. For each test case, there is a number n(0≤n≤1000) on a line representing the number of water sources. n integers follow, respectively a1,a2,a3,...,an, and each integer is in {1,...,106}. On the next line, there is a number q representing the number of queries. After that, there will be q lines with two integers l and r(1≤l≤r≤n) indicating the range of which you should find out the biggest water source.
Output
For each query, output an integer representing the size of the biggest water source.
Sample Input
3
1
100
1
1 1
5
1 2 3 4 5
5
1 2
1 3
2 4
3 4
3 5
3
1 999999 1
4
1 1
1 2
2 3
3 3
Sample Output
100
2
3
4
4
5
1
999999
999999
1
Source
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#include<stdio.h> #include<string.h> #include<iostream> #include<math.h> #include<algorithm> using namespace std; #define N 50005 int dpmin[N][20],dpmax[N][20]; int main() { int t; scanf("%d",&t); while(t--){ int i, j, n, m; scanf("%d",&n); memset(dpmin,0,sizeof(dpmin)); memset(dpmax,0,sizeof(dpmax)); for(i=1; i<=n; i++) { scanf("%d", &dpmin[i][0]); dpmax[i][0]=dpmin[i][0]; } int mm=floor(log(1.0*n)/log(2.0)); for(j=1; j<=mm; j++) for(i=1; i<=n; i++) { if((i+(1<<(j-1)))<=n) { // dpmin[i][j]=min(dpmin[i][j-1], dpmin[i+(1<<(j-1))][j-1]); dpmax[i][j]=max(dpmax[i][j-1], dpmax[i+(1<<(j-1))][j-1]); } } int x, y; scanf("%d",&m); for(int i=1; i<=m; i++) { scanf("%d%d", &x, &y); int mid=floor(log(y*1.0-x+1)/log(2.0)); int maxnum=max(dpmax[x][mid], dpmax[y-(1<<mid)+1][mid]); // int minnum=min(dpmin[x][mid], dpmin[y-(1<<mid)+1][mid]); printf("%d ", maxnum); } } return 0; }