Problem A
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 206947 Accepted Submission(s):
48397
Problem Description
Given a sequence a[1],a[2],a[3]......a[n], your job is
to calculate the max sum of a sub-sequence. For example, given (6,-1,5,4,-7),
the max sum in this sequence is 6 + (-1) + 5 + 4 = 14.
Input
The first line of the input contains an integer
T(1<=T<=20) which means the number of test cases. Then T lines follow,
each line starts with a number N(1<=N<=100000), then N integers
followed(all the integers are between -1000 and 1000).
Output
For each test case, you should output two lines. The
first line is "Case #:", # means the number of the test case. The second line
contains three integers, the Max Sum in the sequence, the start position of the
sub-sequence, the end position of the sub-sequence. If there are more than one
result, output the first one. Output a blank line between two cases.
Sample Input
2
5 6 -1 5 4 -7
7 0 6 -1 1 -6 7 -5
Sample Output
Case 1:
14 1 4
Case 2:
7 1 6
简单题意:
求最大子段和,,并记录位置。。。
简单思路:
第一个DP,写的比较艰难,,,,用从第一个开始求最大子段和,再判断下一个数的最大子段和
#include <iostream> #include <fstream> #include <cstdio> using namespace std; int main() { //fstream cin("aaa.txt"); int t, jishu = 1; cin >> t; while (t--) { int n, dp = 0, max = -1000001, r = 1, l = 1, temp = 1; cin >> n; for(int i = 1; i <= n; i++) { int tep; cin >> tep; dp += tep; if (dp > max) { max = dp; r = temp; l = i; } if (dp < 0) { dp = 0; temp = i + 1; } } printf("Case %d:\n%d %d %d\n", jishu++, max, r, l); if (t != 0) cout << endl; } return 0; }