Ultraviolet A 507 Jill rides again (Search)

Connection: 507-Jill rides again

To put it simply, it is to find the maximum sum of the continuous sequence, but the difference is that the output starts from the first few to the last few.

Solution: you only need to return the maximum range when grouping, but note that when the continuous sequence is divided into the left and right sides, consider the subscript problem during the maximum solution.

#include <stdio.h>#include <string.h>const int N = 20005;int maxsum(int *A, int x, int y, int &frist, int &end) {    if (x == y - 1) {frist = x;end = y;return A[x];    }    int cur = x + (y - x) / 2;    int p1, p2, p3, q1, q2, q3, Max, v, L = A[cur - 1], R = A[cur];    int a = maxsum(A, x, cur, p1, q1);    int b = maxsum(A, cur, y, p2, q2);    if (a > b) {Max = a;frist = p1, end = q1;    }    else if (a < b) {Max = b;frist = p2, end = q2;    }    else {Max = b;if (q1 - p1 >= q2 - p2)    frist = p1, end = q1;else    frist = p2, end = q2;    }    v = 0, p3 = cur - 1;    for (int i = cur - 1; i >= x; i--) {v += A[i];if (v >= L) {    L = v;    p3 = i;}    }    v = 0, q3 = cur;    for (int i = cur; i < y; i++) {v += A[i];if (v >= R) {    R = v;    q3 = i;}    }    q3++;    if (Max < R + L) {frist = p3, end = q3;return R + L;    }    else if (Max > R + L)return Max;    else {if (q3 - p3 > end - frist)    frist = p3, end = q3;else if (q3 - p3 == end - frist && p3 < frist)    frist = p3, end = q3;return Max;    }}int sta[N];int main() {    int t, cas = 1, n, frist, end;    scanf("%d", &t);    while (t--) {scanf("%d", &n);memset(sta, 0, sizeof(sta));for (int i = 0; i < n - 1; i++)    scanf("%d", &sta[i]);if (maxsum(sta, 0, n - 1, frist, end) < 0)    printf("Route %d has no nice parts\n", cas++);else    printf("The nicest part of route %d is between stops %d and %d\n", cas++, frist + 1, end + 1);    }    return 0;}