Time Limit: 1000MS | Memory Limit: 32768KB | 64bit IO Format: %I64d & %I64u |
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
题意不说 和hdu1231很相似 刚刚写了1231,但被这题坑了 maxsum我开始初值设了0 一直wa
后面测试数据才发现自己错了
#include<iostream> #include<cstdio> #include<cmath> #include<cstring> #include<algorithm> typedef long long ll; #define N 100005 using namespace std; int a[N]; int b[N]; ll dp[N]; int main() { int t; int n; int i,j; int first,next; scanf("%d",&t); for(j=1;j<=t;j++) { ll maxsum=-99999999; scanf("%d",&n); for(i=1;i<=n;i++) { scanf("%d",&a[i]); } memset(dp,0,sizeof(dp)); first=1; for(i=1;i<=n;i++) { if(dp[i-1]+a[i]>=a[i]) dp[i]=dp[i-1]+a[i]; else { dp[i]=a[i]; first=i; } b[i]=first; maxsum=max(maxsum,dp[i]); } for(i=1;i<=n;i++) { if(maxsum==dp[i]) { next=i; //break; } } printf("Case %d: ",j); if(j!=t) printf("%I64d %d %d ",maxsum,b[next],next); else printf("%I64d %d %d ",maxsum,b[next],next); } return 0; }