codeforces727C(交互)

#include<cstdio>
using namespace std;
int N, aaa[3], ans[5001], a, b, c;
int main() {
    scanf("%d", &N);
    puts("? 1 2"); fflush(stdout); scanf("%d", &aaa[0]);
    puts("? 2 3"); fflush(stdout); scanf("%d", &aaa[1]);
    puts("? 1 3"); fflush(stdout); scanf("%d", &aaa[2]);
    int aa = a, bb = b, cc = c, p;
    b = (aaa[0] + aaa[1] - aaa[2]) / 2;
    a = aaa[0] - b; c = aaa[1] - b; 
    ans[1] = a; ans[2] = b; ans[3] = c;
    for(int i = 4; i <= N; i++) {
        printf("? 1 %d\n", i); fflush(stdout); scanf("%d", &p);
        ans[i] = p - a;
    }
    printf("! ");
    for(int i = 1; i <= N; i++)
        printf("%d ", ans[i]);
    return 0;
}
/*
5
10
7
5
9
9


4 6 1 5 5 
*/