PAT答案（科学计数法）

た入场券 2022-05-26 06:47 256阅读 0赞

#### 题目链接 ####

[https://www.nowcoder.com/pat/6/problem/4050][https_www.nowcoder.com_pat_6_problem_4050]

#### 代码 ####

#include<iostream>
    #include<math.h>
    #include<string>
    #include<queue>
    #include<stack>
    using namespace std;
    
    int main() {
        string s;
        queue<int> a;
        stack<int> b;
        char symbol;
        int first, i;
        cin >> s;
        first = s[1] - '0';
        for(i=3; ; i++) {
            if(s[i] == 'E') break;
            a.push(s[i] - '0');
        }
        symbol = s[++i];
        for(++i; i<s.length(); i++) b.push(s[i] - '0');
        if(s[0] == '-') printf("-");
        int t = 0, sum = 0;
        while(!b.empty()) {
            sum += b.top() * pow(10, t++);
            b.pop();
        }
        if(symbol == '-') {
            if(sum == 0) printf("%d.", first);
            else {
                printf("0.");
                for(int j=0; j<sum-1; j++) printf("0");
                printf("%d", first);
            }
            while(!a.empty()) {
                printf("%d", a.front());
                a.pop();
            }
        } else {
            if(sum == 0) {
                printf("%d.", first);
                while(!a.empty()) {
                    printf("%d", a.front());
                    a.pop();
                }
            } else {
                printf("%d", first);
                int k = 0, flag = 1;
                while(!a.empty()) {
                    k++;
                    if(k > sum && flag) { printf("."); flag = 0;}
                    printf("%d", a.front());
                    a.pop();
                }
                for(; k < sum; k++) printf("0");
            }
        }
        printf("\n");
        return 0;
    }

[https_www.nowcoder.com_pat_6_problem_4050]: https://www.nowcoder.com/pat/6/problem/4050