最大子段和 C语言源码

#include <stdio.h>typedef struct {    size_t st;    size_t end;    int sum;} ArraySection;/* 求整型数组的最大子段和，结果存于ret */void max_section(int *arr, size_t len, ArraySection *ret) {    size_t st = 0, end = 0;    int sum = *arr;// sum：以当前元素为结尾的所有子段中，子段和最大者    size_t i;    ret->st = ret->end = 0;    ret->sum = sum;    for (i = 1; i < len; ++i) {        if (sum < 0) {            sum = arr[i];            end = st = i;        } else {            ++end;            sum += arr[i];        }        if (sum > ret->sum) {            ret->st = st;            ret->end = end;            ret->sum = sum;        }    }}/* 测试代码 */int main() {    ArraySection as = { 0, 0, 0 };    int arr[] = { -12, 23, 34, -4, -12, 128 };    max_section(arr, sizeof(arr) / sizeof(*arr), &as);    printf("st=%u\nend=%u\nsum=%i\n", as.st, as.end, as.sum);    return 0;}