2014百度之星初赛第二轮代码注释：Scenic Popularity

http://star.baidu.com/forum/forum.php?mod=viewthread&tid=3186&extra=page%3D1

题链接

#include <stdio.h>#include <string.h>const int MAXN = 10000;const int MAXM = 100000;int n;int coord[MAXN];int heat_value[MAXN];int is_scenic[MAXN];int lscenic_idx[MAXN];int rscenic_idx[MAXN];int range_count[MAXM + 1];//l休息区前面的下标，m休息区的下标，r休息区后面的下标，inline int cmp_coord(int l, int m, int r){if (l == -1) return 1;//前面为休息区时返回1if (r == -1) return -1;//后面为休息区时返回-1int d = (coord[m] - coord[l]) - (coord[r] - coord[m]);//休息区距离和前面的景区(好像也可以是休息区，两个休息区可以连着吗)的距离-休息区距离和后面的景区的距离return d == 0 ? 0 : (d < 0 ? -1 : 1);//休息区距离和前面的景区的距离近时d < 0 返回 -1，反正为1，为0返回0}void update(){memset(range_count, 0, sizeof(range_count));for (int s = 0; s < n; s++) {if (is_scenic[s] == 0) {//休息区int l = lscenic_idx[s];int r = rscenic_idx[s];int c = cmp_coord(l, s, r);if (c == 0) {//距离一样heat_value[s] = (heat_value[l] >= heat_value[r] ? heat_value[l] : heat_value[r]);} else if (c < 0) {//休息区距离和前面的景区的距离近,或者后面不是景区时heat_value[s] = heat_value[l];} else {//休息区距离和后面的景区的距离近,或者前面不是景区时heat_value[s] = heat_value[r];}}range_count[heat_value[s]]++;//热度值为heat_value[s]的+1}}//给lscenic_idx，rscenic_idx赋值void init_data(){for (int i = 0; i < n; i++) {lscenic_idx[i] = (is_scenic[i] == 1 ? i : (i == 0 ? -1 : lscenic_idx[i - 1]));//is_scenic[i]为休息区时lscenic_idx[i]为上一个的下标（i为0时为-1），is_scenic[i]为景点区时为下标}for (int i = n - 1; i >= 0; i--) {rscenic_idx[i] = (is_scenic[i] == 1 ? i : (i == n - 1 ? -1 : rscenic_idx[i + 1]));//is_scenic[i]为休息区时lscenic_idx[i]为下一个的下标（i为最后一个下标时为-1），is_scenic[i]为景点区时为下标}update();}    int query(int range){int cnt = 0;for (int i = 1; i <= range; i++) {cnt += range_count[i]; }return cnt;}int main(){int KK = 1;int T, Q;char cmd[10];scanf("%d", &T);while (T--) {scanf("%d", &n);for (int i = 0; i < n; i++) {scanf("%d %d", &coord[i], &heat_value[i]);is_scenic[i] = (heat_value[i] > 0 ? 1 : 0);//如果为休息区is_scenic为0}init_data();printf("Case #%d:\n", KK++);scanf("%d", &Q);while (Q--) {int s, chv, range;scanf("%s", cmd);if (cmd[0] == 'U') {scanf("%d %d", &s, &chv);heat_value[s] = chv;//改变风景区热度值update();//更改休息区热度值} else {scanf("%d", &range);printf("%d\n", query(range));}}}return 0;}