01-复杂度2 Maximum Subsequence Sum (25 分)
Given a sequence of KKK integers {N1,N2,…,NK}\{ N_1, N_2, \dots, N_K \}{N1,N2,…,NK}. A continuous subsequence is defined to be {Ni,Ni+1,…,Nj}\{ N_i, N_{i+1}, \dots, N_j \}{Ni,Ni+1,…,Nj} where 1≤i≤j≤K1≤i≤j≤K1≤i≤j≤K. The Maximum Subsequence is the continuous subsequence which has the largest sum of its elements. For example, given sequence { -2, 11, -4, 13, -5, -2 }, its maximum subsequence is { 11, -4, 13 } with the largest sum being 20.
Now you are supposed to find the largest sum, together with the first and the last numbers of the maximum subsequence.
Input Specification:
Each input file contains one test case. Each case occupies two lines. The first line contains a positive integer KKK (≤10000). The second line contains KKK numbers, separated by a space.
Output Specification:
For each test case, output in one line the largest sum, together with the first and the last numbers of the maximum subsequence. The numbers must be separated by one space, but there must be no extra space at the end of a line. In case that the maximum subsequence is not unique, output the one with the smallest indices iii and jjj (as shown by the sample case). If all the KKK numbers are negative, then its maximum sum is defined to be 0, and you are supposed to output the first and the last numbers of the whole sequence.
Sample Input:
10
-10 1 2 3 4 -5 -23 3 7 -21
Sample Output:
#include <stdio.h>
int main(void) {
int N = 0;
int arr[100000];
int thisSub=0,sumSub=0;
int S=0,D=0,Dmax=0,Smax=0;
scanf("%d",&N);
for(int i =0 ;i<N;i++){
scanf("%d",arr+i);
}
for(int i =0;i < N;i++){
thisSub += arr[i];
if(thisSub >= 0){
D=i;
if(thisSub > sumSub||thisSub==0&&sumSub==0){
sumSub = thisSub;
Smax=S;
Dmax=D;
}
}
else {
S = i+1;
thisSub = 0;
}
}
printf("%d %d %d",sumSub,arr[Smax],arr[Dmax==0?N-1:Dmax]);
return 0;
}

本文深入探讨了最大子序列和问题,这是一个经典的算法问题,旨在从整数序列中找到连续子序列的最大和。文章提供了详细的输入输出规范,并通过一个示例展示了如何使用C语言实现该算法。此外,还讨论了当所有数为负数时的特殊情况处理。
405

被折叠的 条评论
为什么被折叠?



