做一个水题,回去歇着了……
/*
POJ: 1276 Cash Machine
*/
#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <set>
using namespace std;
struct Case {
int n, d;
} cash[15];
bool deliver[100005];
int C, N;
int main()
{
while(scanf("%d%d", &C, &N) != EOF) {
for(int i = 0; i < N; i++)
scanf("%d%d", &cash[i].n, &cash[i].d);
memset(deliver, false, sizeof(deliver));
deliver[0] = true;
for(int i = 0; i < N; i++) {
for(int j = C; j >= 0; j--) {
if(deliver[j]) {
for(int k = 1; k <= cash[i].n; k++) {
if(j + k * cash[i].d <= C)
deliver[j + k * cash[i].d] = true;
else
break;
}
}
}
}
for(int i = C; i >= 0; i--) {
if(deliver[i]) {
printf("%d\n", i);
break;
}
}
}
return 0;
}