第四章 ALDS1_3_D:Areas on the Cross-Section Diagram

问题链接

ALDS1_3_D:Areas on the Cross-Section Diagram

问题内容

求出每个积水处的横截面积

思路

利用栈的思想去做

• 如果是’\’则将该字符的位置i压入栈
• 如果是’/’则从栈顶取出与之对应的’\’的位置ip
• 累加两者距离i−ip,结果即为总面积

代码

#include<iostream>#include<cstdio>#include<cstring>#include<vector>#include<stack>#include<algorithm>using namespace std;int main() {    stack<int> S1;    stack<pair<int, int> >S2;    char s[20000 + 10];    scanf("%s", s);    int i = 0, sum = 0;    while (s[i] != '\0') {        // 若是\则压入栈        if (s[i] == '\\')            S1.push(i);        else if (s[i] == '/' && !S1.empty()) {            int j = S1.top(); S1.pop();            // 加上新形成的面积            sum += i - j;            int a = i - j;            // 同一块的合在一起            while (!S2.empty() && S2.top().first > j) {                a += S2.top().second; S2.pop();            }            S2.push(make_pair(j, a));        }        i++;    }    vector<int> ans;    while (!S2.empty()) {        ans.push_back(S2.top().second);        S2.pop();    }    printf("%d\n", sum);    int len = ans.size();    printf("%d", len);    for (int i = len - 1; i >= 0; i--) {        printf(" %d", ans[i]);    }    printf("\n");    return 0;}