题解 | #合并区间#

/**
 * struct Interval {
 *	int start;
 *	int end;
 * };
 */
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param intervals Interval类一维数组 
 * @param intervalsLen int intervals数组长度
 * @return Interval类一维数组
 * @return int* returnSize 返回数组行数
 */
#define max(a,b) a>b?a:b
int compare(const void* a, const void* b) {
    struct Interval *A = (struct Interval*)a;
    struct Interval *B = (struct Interval*)b;
    return A->start - B->start;
}


struct Interval* merge(struct Interval* intervals, int intervalsLen, int* returnSize ) {
    // write code here
    if (intervalsLen == 1) {
        *returnSize = 1;
        return intervals;
    }
    qsort(intervals, intervalsLen, sizeof(struct Interval), compare);
    for(int i = 0; i < intervalsLen; i++) {
        printf("start:intervals[%d].start%d\nend:intervals[%d].end%d\n",i,intervals[i].start,i,intervals[i].end);
    }
    *returnSize = 0;
    struct Interval * result = (struct Interval*)malloc(sizeof(struct Interval) * intervalsLen);
    int idx = 0;
    while(idx < intervalsLen) {
        struct Interval new;
        new.start = intervals[idx].start;
        new.end = intervals[idx].end;
        idx++;
        while(idx < intervalsLen && new.end >= intervals[idx].start) {
            printf("max of %d and %d is %d\n",new.end, intervals[idx].end, max(new.end, intervals[idx].end));
            new.end = max(new.end, intervals[idx].end);
            idx++;
        }
        result[(*returnSize)] = new;
        (*returnSize)++;
    }
    return result;
}