python/TangDou/LuoGuBook/P1307_Array.cpp

#include <bits/stdc++.h>

using namespace std;
const int N = 110;
int a[N], idx;
// 1234000
int main() {
    int n;
    cin >> n;

    if (n == 0) {
        cout << 0 << endl;
        exit(0);
    }
    if (n < 0) {
        cout << "-";
        n = -n;
    }

    while (n) {
        a[++idx] = n % 10; //由后到前 4 3 2 1 --> a[1]=4 a[2]=3
        n /= 10;
    }

    bool flag = false; //是不是已经遇到过一个非零数字
    for (int i = 1; i <= idx; i++) {
        if (a[i] != 0) flag = true;
        if (a[i] == 0) {
            if (flag) cout << 0;
        } else
            cout << a[i];
    }

    return 0;
}