Ultraviolet A 11237-Halloween treats (Drawer principle)

Link: Ultraviolet A 11237-Halloween treats

There are c children who want to go to the neighbor's house to ask for candy. There are n neighbors who only provide a fixed number of sweets. The bear children do not conflict with each other, I decided to distribute the obtained candy evenly. I asked if I could evenly distribute the candy from those neighbors. Note that N is greater than or equal to C.

Solution concept: Drawer principle, finding the prefix and number of sequences, there are N. After the prefix and Modulo for C are obtained, the theorem of the remainder series must be in the range of 0 ~ If the value is 0, the answer is needless to say. If the prefix and the remainder of the two ends indicate that the sum of the middle section is a multiple of C. And because N is greater than or equal to C, there must be a solution for getting 0, so the number of N corresponds to the location of C-1, and there must be the same remainder.

#include <cstdio>#include <cstring>#include <algorithm>using namespace std;const int maxn = 100000;int a[maxn+5], s[maxn+5], vis[maxn+5];int main () {    int c, n;    while (scanf("%d%d", &c, &n) == 2 && c + n) {        for (int i = 1; i <= n; i++)            scanf("%d", &a[i]);        memset(vis, -1, sizeof(vis));        vis[0] = s[0] = 0;        for (int i = 1; i <= n; i++) {            s[i] = (s[i-1] + a[i]) % c;            if (vis[s[i]] == -1)                vis[s[i]] = i;            else {                for (int j = vis[s[i]] + 1; j <= i; j++)                    printf("%d%c", j, j == i ? ‘\n‘ : ‘ ‘);                break;            }        }    }    return 0;}