[CF]A. Gabriel and Caterpillar
題目: http://codeforces.com/problemset/problem/652/A --------------------------------------------------------------------------------- #include <bits/stdc++.h> using namespace std; const int n = 4e5 + 5; int main() { int h1, h2; int a, b; scanf("%d%d",&h1,&h2); scanf("%d%d",&a,&b); h1 += 8 * a; if(h1 >= h2){ printf("0\n"); return 0; } h1 -= 12 * b; if(a <= b){ printf("-1\n"); return 0; } int day = 1; for(int i=0;i<n;i++){ h1 += 12 * a; if(h1 >= h2){ printf("%d\n",day); return 0; } h1 -= 12 * b; day++; } printf("-1\n"); return 0; }